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Erythema elevatum diutinum is a rare, chronic cutaneous leukocytoclastic vasculitis, with prominent fibrosis at its later stage. In this article, we report a case of erythema elevatum diutinum in a 23-year-old woman with well-controlled Crohn disease. To our knowledge, erythema elevatum diutinum has been reported in only three other cases of Crohn disease, in which eruptions of erythema elevatum diutinum were associated with features of active Crohn. Our patient was in clinical remission at the time of erythema elevatum diutinum onset, making this report significant not only for its uncommon presentation, but more importantly, to aid readers. diagnosis and clinical management of similar cases.

Background: Chronic myeloid leukaemia (CML) is a haematopoietic stem cell disease characterised by the proliferation of granulocytes and their immature myeloid precursors. The treatments recommended are oral treatments dispensed in the outpatient unit (OU) of the hospital's pharmacy service (PS), where patient-centred pharmaceutical care (PC) is essential to enhance therapeutic adherence, detect drug interactions and create a pharmacist-patient relationship to educate the patient on the main potential toxicities derived from the treatment and warning signs or symptoms requiring immediate attention. Methodology: We present the case of a 55-year-old woman, followed up in consultation by the Haematology Service (HS) since October 2021 for CML in the chronic phase. Results: She started treatment on nilotinib 300 mg every 12 hours. The patient attended OU and was offered PC. After 12 months, nilotinib was well tolerated, but our patient experienced a loss of effectiveness, so HS decided to switch to dasatinib 100 mg daily. After one year of treatment, our patient was presented with symptoms of swelling and dyspnoea on moderate exertion. In January 2024, following a joint Haematology-Pharmacy session, a switch to bosutinib 400 mg daily was decided. After 15 days of treatment, the patient presented without an appointment due to a pruritic generalised rash on the torso, face, and extremities, being diagnosed with leukocytoclastic vasculitis. Conclusion: In conclusion, we describe case reports of a patient who has a lack of effectiveness and ARs in several TKIs and the importance of identifying side effects, through early and close PC, in order for the patient's evolution to be favourable. [ABSTRACT FROM AUTHOR]

Background: Due to the immune‐mediated nature of non‐infectious cutaneous vasculitis, skin biopsy specimens are often submitted for direct immunofluorescence (DIF) testing when vasculitis is considered clinically. However, evidence regarding the clinical value of DIF has not been rigorously appraised. Objective: In this scoping review, we aimed to systematically evaluate the peer‐reviewed literature on the utility of DIF in vasculitis to assist with the development of appropriate use criteria by the American Society of Dermatopathology. Methods: Two electronic databases were searched for articles on DIF and vasculitis (January 1975–October 2023). Relevant case series involving more than or equal to three patients, published in English, and with full‐text availability were included. Additional articles were identified manually via reference review. Due to study heterogeneity, findings were analyzed descriptively. Results: Of 255 articles identified, 61 met the inclusion criteria. Cumulatively representing over 1000 DIF specimens, several studies estimated DIF sensitivity to be 75%. While vascular immunoglobulin A (IgA) deposits on DIF were associated with renal disease, other systemic associations were inconsistent. Vascular IgG deposition may be overrepresented in ANCA‐associated vasculitis. Granular vascular and epidermal basement membrane zone Ig deposition differentiated hypocomplementemic from normocomplementemic urticarial vasculitis. Few studies have assessed the added value of DIF over routine microscopy alone in vasculitis. Conclusions: This scoping review discovered that DIF testing for vasculitis has been performed not only for diagnostic confirmation of vasculitis but also for disease subtype classification and prediction of systemic associations. Future studies on test sensitivity of DIF compared to that of histopathology are needed. [ABSTRACT FROM AUTHOR]

Objective: Rare disease Objective: Rare disease Background: One percent of paraneoplastic syndromes described in the literature present as cutaneous manifestations such as vasculitis, which may reveal potential initial diagnoses. Leukocytoclastic vasculitis is a subtype of small-vessel vasculitis. It affects the skin and internal organs, and diagnosis relies solely on histopathological examination. The literature on leukocytoclastic vasculitis linked with malignancies is scarce. Case Report: We present the case of a 60-year-old man with multiple cardiovascular comorbidities, presenting with dysuria and elevated prostate-specific antigen (PSA) levels. Further investigations led to diagnosis of metastatic prostate adenocarcinoma. Concurrently, he developed non-specific cutaneous lesions. He underwent hormonal therapy and radiotherapy. During initial treatment, the lesions rapidly progressed to necrotic ulcers; therefore, hormonal therapy was withheld. Extensive investigations ruled out potential infectious or rheumatological causes of the lesions, and histopathological analysis was consistent with cutaneous leukocytoclastic vasculitis. The patient underwent systemic corticoid treatment while continuing radiotherapy. Following completion of radiation therapy and a corticosteroid course, the patient showed good clinical response, with decreased PSA level, resolution of urological symptoms, and clinical improvement of the lesions. He was cleared for hormonal treatment continuation. Conclusions: Given the temporal relationship between the onset of vasculitis, its exacerbation during first days of cancer treatment initiation and the rapid resolution following radiotherapy, a paraneoplastic etiology for leukocytoclastic vasculitis can be considered in this case. While the literature on leukocytoclastic vasculitis associated with malignancies is limited, clinicians must maintain vigilance to ensure timely and accurate diagnosis. Background: One percent of paraneoplastic syndromes described in the literature present as cutaneous manifestations such as vasculitis, which may reveal potential initial diagnoses. Leukocytoclastic vasculitis is a subtype of small-vessel vasculitis. It affects the skin and internal organs, and diagnosis relies solely on histopathological examination. The literature on leukocytoclastic vasculitis linked with malignancies is scarce. Case Report: We present the case of a 60-year-old man with multiple cardiovascular comorbidities, presenting with dysuria and elevated prostate-specific antigen (PSA) levels. Further investigations led to diagnosis of metastatic prostate adenocarcinoma. Concurrently, he developed non-specific cutaneous lesions. He underwent hormonal therapy and radiotherapy. During initial treatment, the lesions rapidly progressed to necrotic ulcers; therefore, hormonal therapy was withheld. Extensive investigations ruled out potential infectious or rheumatological causes of the lesions, and histopathological analysis was consistent with cutaneous leukocytoclastic vasculitis. The patient underwent systemic corticoid treatment while continuing radiotherapy. Following completion of radiation therapy and a corticosteroid course, the patient showed good clinical response, with decreased PSA level, resolution of urological symptoms, and clinical improvement of the lesions. He was cleared for hormonal treatment continuation. Conclusions: Given the temporal relationship between the onset of vasculitis, its exacerbation during first days of cancer treatment initiation and the rapid resolution following radiotherapy, a paraneoplastic etiology for leukocytoclastic vasculitis can be considered in this case. While the literature on leukocytoclastic vasculitis associated with malignancies is limited, clinicians must maintain vigilance to ensure timely and accurate diagnosis. [ABSTRACT FROM AUTHOR]

With the global introduction and widespread administration of COVID-19 vaccines, there have been emerging reports of associated vasculitis, including leukocytoclastic cutaneous vasculitis (LCV). In this paper, we present a case of a 68-year-old female patient who developed painful purpuric skin lesions on her feet 12 days after administration of the inactivated COVID-19 vaccine BBIBP Cor-V with histopathological confirmation of LCV and no signs of systemic involvement. The case is followed by a comprehensive literature review of documented LCV cases associated with COVID-19 vaccination with overall 39 articles and 48 cases of LCV found in total. In the majority of cases (56.3%) the first symptom occurred after the first dose of the COVID-19 vaccine, with symptoms manifesting within an average of seven days (6.8 ± 4.8) post-vaccination. The adenoviral vaccine Oxford-AstraZeneca (41.7%) and the mRNA vaccine Pfizer-BioNTech (27.1%) were most frequently associated with LCV occurrences. On average, LCV resolved within 2.5 (± 1.5) weeks. The preferred treatment modality were glucocorticoids, used in 70.8% of cases, resulting in a positive outcome in most cases, including our patient. While the safety of a subsequent dose appears favorable based on our review, individual risk–benefit assessment is crucial. This review emphasis the importance of considering COVID-19 vaccination as a potential trigger for the development of cutaneous vasculitis. Despite rare adverse events, the benefits of the COVID-19 vaccination outweigh the risks, highlighting the importance of immunization programs. [ABSTRACT FROM AUTHOR]

Japanese spotted fever is an emerging rickettsiosis caused by Rickettsia japonica and is characterized by high fever, rash, and eschar formation. Other symptoms are often vague and nonspecific and include headaches, nausea, vomiting, and myalgia. We present a case of a 46-year-old woman with Japanese spotted fever, complicated by transient bilateral sensorineural hearing loss and presenting cutaneous IgM/IgG immune complex vasculitis. The patient was admitted with a history of several days of high fever, generalized skin erythema, and hearing impairment. Laboratory findings revealed thrombocytopenia and elevated liver enzyme and C-reactive protein levels. Pure-tone audiometry revealed bilateral sensorineural hearing loss, and a skin biopsy revealed leukocytoclastic vasculitis with deposition of C3 and IgM on the vessel walls. Under the tentative diagnosis of rickettsiosis, scrub typhus, or Japanese spotted fever, the patient was treated with minocycline, and her symptoms improved within approximately 10 days. A definitive diagnosis was made on the basis of a serological test showing increased antibody levels against Rickettsia japonica. Japanese spotted fever can cause transient sensorineural hearing loss, a rare complication that presents with cutaneous IgM/IgG immune complex vasculitis. [ABSTRACT FROM AUTHOR]

Background: Leukocytoclastic vasculitis (LCV) is a vasculitic inflammation against blood vessels. Various anticancer therapies can cause vasculitis, but capecitabine-induced LCV is an unusual entity. Here, we describe an LCV case associated with neoadjuvant capecitabine use for locally advanced rectal cancer (LARC). Case report: A 70-year-old man presented with rectal bleeding. A colonoscopic biopsy revealed rectal adenocarcinoma and he was diagnosed with LARC after imaging studies. Capecitabine plus radiation therapy was started as a neoadjuvant treatment. Management and outcome: Seven days after the first capecitabine dose, the patient was admitted with a rash. The LCV diagnosis was histopathologically proven. Capecitabine was withheld. After the patient's rash began to regress under corticosteroid pressure, capecitabine was started at a lower dose. His treatment was completed successfully with oral corticosteroids plus low-dose capecitabine. Discussion: We aimed to point out a rare and unusual adverse effect of a frequently used drug in oncologic practice. [ABSTRACT FROM AUTHOR]

Capnocytophaga canimorsus is a gram-negative bacterium commonly found in the saliva of dogs and cats. Despite the frequency of animal bites, infection with Capnocytophaga species is rare, and severe infections are usually associated with underlying risk factors, such as alcohol use disorder, asplenia, or immunosuppression. We describe a case of a man who presented with a purpuric rash, lower extremity edema, and acute renal failure and was found to have tricuspid valve endocarditis and infection-associated glomerulonephritis due to C. canimorsus. Despite treatment with cefepime, the vegetation increased in size and valvular function worsened. He was readmitted with an inferior wall myocardial infarction, heart failure, and pulmonary embolism. He underwent an urgent tricuspid valve replacement with a bioprosthetic valve. A 16S ribosomal RNA amplicon sequencing performed on the resected valve tissue verified involvement of C. canimorsus. Post-operatively, he had several episodes of gastrointestinal hemorrhage requiring multiple endoscopic interventions and arterial embolization. The recurrent gastrointestinal hemorrhage combined with his severe functional decline ultimately led to his death. This patient had an uncommon presentation with leukocytoclastic vasculitis and infection-associated glomerulonephritis, which revealed an underlying diagnosis of infective endocarditis due to C. canimorsus, a rare gram-negative bacterial etiology of infective endocarditis. [ABSTRACT FROM AUTHOR]

ABSTRACT A 13‐year‐old girl with fevers, abdominal pain, and vomiting for 4 days presented with a full body pruritic rash that began in the axilla and spread rapidly to the rest of the body. She was recently diagnosed with tuberculosis and had been on rifampin, isoniazid, pyrazinamide and ethambutol (RIPE) therapy for 1 month to treat this infection, raising concern for a severe drug reaction. On exam, there were pink to hemorrhagic crusted papules diffusely on the body; two skin biopsies from the right ankle and right arm showed leukocytoclastic vasculitis and tuberculid pathologies, respectively. Tuberculids are a cutaneous form of tuberculosis that represent a hypersensitivity reaction to Mycobacterium tuberculosis or its antigens. These rashes can mimic other common diseases, and this case highlights the importance of obtaining histopathology early in the disease course for accurate and prompt diagnosis. [ABSTRACT FROM AUTHOR]

This article discusses a case of IgA vasculitis in a patient with ulcerative colitis who was undergoing treatment with vedolizumab. IgA vasculitis is a rare symptom associated with ulcerative colitis, and vedolizumab is an antibody used to treat inflammatory bowel diseases. The patient experienced pulmonary hemorrhage and purpura on her limbs, which were preceded by episodes of hemoptysis. The article suggests that the development of IgA vasculitis may have been triggered by a combination of factors, including the alteration of intestinal microbiota due to vedolizumab treatment and lower respiratory tract infection. The patient's symptoms improved with prednisolone treatment, and there was no recurrence of symptoms after discontinuing prednisolone. The article concludes by stating that further research is needed to determine if vedolizumab increases the risk of IgA vasculitis in patients with inflammatory bowel disease. [Extracted from the article]

Introduction: Leukocytoclastic vasculitis (LCV) is a small vessel vasculitis involving arterioles, capillaries and postcapillary venules. LCV is generally confined to the skin, with extracutaneous manifestations occurring less frequently. LCV has multiple potential etiologies. Indeed, histological LCV can be found in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, immune complex vasculitis, vasculitis associated with systemic diseases (i.e. sarcoidosis, Sjögren's syndrome, rheumatoid arthritis, and systemic lupus erythematosus), or in vasculitis associated with cancer, infections, sepsis and use of certain medications. LCV can also be idiopathic in up to 50% of cases. Case report: Semaglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist used for management of type 2 diabetes mellitus (T2DM), obesity and overweight associated with one or more weight-related comorbidities. A case of drug-induced LCV has already been described with the use of once-daily oral semaglutide. Herein, we describe the first case of skin-limited LCV induced by once-weekly subcutaneous semaglutide in a 73-year-old man with T2DM, who experienced the complete resolution of the skin lesions shortly after the discontinuation of semaglutide therapy. Conclusion: Future prospective studies, adverse event reporting and post-marketing surveillance will certainly contribute to establishing if LCV represents a less rare than expected side effect of both oral and subcutaneous semaglutide formulations. [ABSTRACT FROM AUTHOR]

Urticarial vasculitis is characterized by persistent urticarial lesions lasting over 24 h. Urticarial vasculitis is often triggered by medications, infections, and autoimmune disorders. However, vaccinations against viral and bacterial pathogens have recently been documented to induce urticarial vasculitis. We describe the case of a 67-year-old woman who was presented with an extensive erythematous and purpuric rash without systemic symptoms 3 days after an influenza vaccination. She was diagnosed with normocomplementemic urticarial vasculitis based on clinical findings, normal complement levels, and histopathological findings of leukocytoclastic vasculitis. After receiving oral histamines, she showed complete resolution 3 months after receiving the influenza vaccination. Although vaccination-associated vasculitis is common, urticarial vasculitis following vaccinations is rare. We reviewed 13 cases of urticarial vasculitis following a wide range of vaccines, including those against Bacillus Calmette–Guérin, serogroup B meningococcus, influenza, and coronavirus disease. We conducted a comprehensive review of various aspects, including age, sex, past medical history, type of vaccination, number of vaccinations, onset time, cutaneous symptoms, place of eruption, systemic symptoms, laboratory disorders, treatment period, and treatment of urticarial vasculitis. Two patients developed hypocomplementemic urticarial vasculitis after vaccination, and both experienced systemic symptoms such as arthralgia and fever. In this review, no significant differences were found in the data, which may be attributed to the small number of cases. The mechanisms underlying the induction of urticarial vasculitis by vaccines remain unknown; however, in addition to immune complex deposition and complement activation due to vaccine components, molecular mimicry may trigger urticarial vasculitis by producing vaccine-derived pathogenic antigen antibodies. This case study emphasizes the need for heightened awareness and further investigation of urticarial vasculitis as a rare adverse effect of vaccination. [ABSTRACT FROM AUTHOR]

The document titled "Synopses from Surveillance" provides information on the investigation of suspected cases of emerging or exotic diseases in horses in New Zealand. The investigation team is interested in hearing about any unusual equine health issues, including parasites, unexplained diseases in recently imported horses, and unexplained outbreaks in groups of horses. The document includes specific cases, such as a suspected case of equine infectious anemia in a Standardbred mare, a case of exertional rhabdomyolysis in an Arab mare, and various other diagnostic cases. The document also mentions the exclusion of exotic diseases and the potential causes of the observed health issues. [Extracted from the article]

A 73-year-old man with lung squamous cell carcinoma was administered carboplatin + nab-paclitaxel + pembrolizumab for four cycles. Subsequently, he presented with multiple purpuras on his extremities, joint swelling on his fingers, abdominal pain, and diarrhea, accompanied by acute kidney injury (AKI), increased proteinuria, hematuria, and elevated C-reactive protein levels. Skin biopsy showed leukocytoclastic vasculitis as well as IgA and C3 deposition in the vessel walls. Based on these findings, the patient was diagnosed with IgA vasculitis as an immune-related adverse event (irAE) induced by carboplatin + nab-paclitaxel + pembrolizumab. After discontinuation of pembrolizumab and glucocorticoids, the symptoms immediately resolved. Regular monitoring of skin, blood tests, and urinalysis are necessary, and the possibility of irAE IgA vasculitis should be considered in cases of purpura and AKI during treatment with immune checkpoint inhibitors. [ABSTRACT FROM AUTHOR]

Introduction. The association between Sjögren's syndrome (SS) and the development of lymphoma is well known. The prevalence of lymphoma in patients with SS is 5%. Mucosaassociated lymphoid tissue (MALT) lymphoma is the most common lymphoma type in patients with SS. It is common for MALT lymphoma to develop in the stomach, while it is extremely rare in the thymus. Case report. We present a 61-year-old Caucasian male patient with primary SS, cutaneous vasculitis, and thymic MALT lymphoma. The patient had a two-year history of diffuse cutaneous palpable purpura on legs, intermittently enlarged left parotid gland, and dry mouth. The results of Schirmer's test were positive, labial salivary glands biopsy revealed a focus score = 1, serology testing showed positive anti-Ro/SS-A and anti-La/SS-B antibodies, while skin biopsy findings revealed leukocytoclastic vasculitis. Diagnosis of primary SS with extraglandular cutaneous manifestations was confirmed. Cryoglobulinemia (Cg) and monoclonal gammopathy (MG) were detected, which increased the suspicion of hematological malignancy, and additional diagnostic procedures were performed. Computed tomography of the chest revealed an enlarged, multicystically altered anterior mediastinal mass. A thymectomy was performed through video-assisted thoracic surgery. Histological findings of the tissue confirmed the presence of tumor tissue consistent with MALT lymphoma in the thymus. Induction therapy with pulse doses of glucocorticoids was applied for three days, which was continued with medium doses of the drug. The doses were gradually reduced, and hydroxychloroquine was introduced. This has shown to be an effective therapy against features of SS. Postoperative local radiotherapy was performed. Conclusion. In SS patients with CV and in the presence of Cg and MG, attention should also be paid to the eventual development of MALT lymphoma, including the rare localization in the thymus. [ABSTRACT FROM AUTHOR]

Background Immune complex vasculitides may be subdivided into adult IgA small vessel vasculitis (aIgA-SVV; i.e. adult Henoch–Schönlein purpura) and non-IgA-SVV (hypersensitivity vasculitis, etc.). Objectives To evaluate the clinical and laboratory parameters of inpatients fulfilling the diagnostic criteria for aIgA-SVV and non-IgA-SVV. Methods Twenty-nine adults aged ≥ 20 years with aIgA-SVV [according to the European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society (EULAR/PRINTO/PRES) criteria] and 53 adults with non-IgA-SVV (according to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides) were compared with respect to a variety of clinical and laboratory parameters by uni- and multivariable analyses. Results Compared with patients with aIgA-SVV, the platelet-to-lymphocyte ratio was significantly higher in patients with non-IgA-SVV. Serum C3 levels and mean corpuscular haemoglobin concentration in patients with non-IgA-SVV were significantly lower compared with patients with aIgA-SVV. Proteinuria and haematuria were significantly more common in patients with aIgA SVV, and were significantly correlated with systemic immune-inflammation biomarkers only in patients with aIgA-SVV. In patients with aIgA-SVV, higher lactate dehydrogenase and C-reactive protein were strong independent predictors for the presence of proteinuria and proteinuria. In patients with non-IgA-SVV, female sex was a protective factor for proteinuria, while skin lesions on the upper extremities proved to be a significant independent predictor of haematuria. Conclusions We detected several clinical and laboratory differences between patients with aIgA-SVV and non-IgA-SVV. Distinct predictors for renal involvement were not observed in either group, indicating that aIgA-SVV and non-IgA-SVV are similar conditions but do not appear to represent the same entity. [ABSTRACT FROM AUTHOR]

Summary: This report describes a 2‐year‐old Quarter Horse filly that was diagnosed with concurrent Streptococcus equi subsp. equi infection, purpura haemorrhagica, and immune‐mediated myositis. The filly was presented for evaluation of fever of unknown origin, rapid weight loss and inappetence after exposure to strangles that was initially unknown. Over the course of hospitalisation the filly developed mandibular lymphadenopathy, guttural pouch empyema, and mucosal petechiation and ecchymoses. The presence of Streptococcus equi subsp. equi was confirmed via PCR and culture of a lymph node aspirate and biopsies of the skin confirmed leukocytoclastic vasculitis, consistent with purpura haemorrhagica. Genetic testing confirmed that the filly had one copy of the MYH1 mutation (N/My). Following therapy with systemic corticosteroids, plasma transfusion and antimicrobial therapy the filly improved and was discharged. Communication with the owner 11 months later confirmed that filly appeared healthy but remained poorly muscled. This report is the first to the authors' knowledge describing concurrent Streptococcus equi subsp. equi infection, purpura haemorrhagica, and immune‐mediated myositis. [ABSTRACT FROM AUTHOR]

This article discusses two case reports of patients with vasculitis ulcers who were treated with tofacitinib, a Janus kinase (JAK) inhibitor. Vasculitis is a group of rare diseases that cause inflammation of blood vessels, and vasculitis ulcers can be challenging to treat. The topical application of tofacitinib cream was found to be effective in healing the ulcers in both cases. This treatment approach shows promise for managing vasculitis ulcers, although further research is needed to fully understand its efficacy. [Extracted from the article]

Clinical Key Message: In patients receiving anti‐TNF‐α drugs for ankylosing spondylitis, monitoring purpuric and ischemic skin lesions is crucial. This case underscores the significance of identifying and addressing drug‐induced vasculitis while stressing the necessity for prompt evaluation and exploration of alternative treatment options to safeguard patient well‐being. The case discusses a 38‐year‐old female with a history of ankylosing spondylitis (AS) who presented with skin lesions, including purpuric skin lesions and ischemia of her right foot digits, after initiating treatment with adalimumab. After excluding other potential causes, such as infections and malignancies, the patient received a diagnosis of moderate‐sized vascular vasculitis associated with adalimumab use. Discontinuation of adalimumab and treatment with high dose glucocorticoids and intravenous pulse of cyclophosphamide resulted in the resolution of her ischemic lesions. This case underscores the importance of considering drug‐related side effects in patients with new skin lesions, particularly in the context of rheumatic diseases such as AS. [ABSTRACT FROM AUTHOR]

Erythema elevatum diutinum (EED) is a rare form of chronic cutaneous leukocytoclastic vasculitis that is characterized by the appearance of red or purplish papules, plaques, or nodules on the skin. These lesions are typically found on the extensor surfaces of the limbs, such as the elbows, knees, and ankles. EED is frequently associated with other systemic diseases, such as autoimmune diseases, infections, and malignant diseases, particularly hematologic abnormalities. We report a case of EED in a 41-year-old Caucasian male with a previously unknown diagnosis of HIV infection. The treatment was performed with oral dapsone, resulting in complete regression of the lesions after 1 year of treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Leukocytoclastic vasculitis is mediated by a type III hypersensitivity reaction. This entity is the most common vasculitis in clinical practice and is associated with a wide spectrum of conditions: autoimmune, neoplasms, infections, or drug hypersensitivity. Leukocytoclastic vasculitis is an infrequent manifestation of hypersensitivity to drugs; pharmacodermias only cause between 10 and 24% of cases; the most common causative agents are nonsteroidal anti-inflammatory drugs, beta-lactam antibiotics, or sulfa drugs. Clinically it manifests as palpable purpura that predominates in the lower extremities and trauma sites. Treatment focuses on symptom control, low-dose corticosteroids, or colchicine. When the cause is a medication, the prognosis is favorable and the suspension of the causative drug is usually healing. CLINICAL CASE: Case 1: A 31-year-old male patient who presented, after consuming ketorolac, a dermatosis of both legs with purpuric spots and blisters with a necrotic center, that subsided after 5 days. Case 2: A 45-year-old male patient who manifested purpuric spots and blisters 12 hours after consuming naproxen. CONCLUSIONS: Nonsteroidal anti-inflammatory drugs can potentially precipitate leukocytoclastic vasculitis, and early diagnosis and treatment reduce morbidity in adults. [ABSTRACT FROM AUTHOR]

We describe the case of a 19-year-old woman who presented with abdominal pain, vomiting, and a palpable purpuric rash. The patient subsequently developed dysentery and was found to have an infection from Shiga toxin–producing Escherichia coli. The patient also met diagnostic criteria for IgA vasculitis (also known as Henoch Schönlein purpura) but had negative immunofluorescence biopsies of the rash. The patient was treated with steroids and achieved recovery. To our knowledge, this is the first documented case of IgA vasculitis in the setting of an enterohemorrhagic E. coli infection. This case highlights an atypical presentation of IgA vasculitis and the need to include small vessel vasculitis as a differential diagnosis when treating patients of all ages. [ABSTRACT FROM AUTHOR]

The article discusses a case study of a 28-year-old woman from India presenting with painful ulcers on her legs, suggestive of Lucio phenomenon (LP) in leprosy. Mycobacterium lepromatosis was identified in the patient, emphasizing the importance of early detection and treatment in non-endemic countries. The study highlights the clinical and epidemiological significance of LP and the need for timely intervention to prevent severe complications associated with M. lepromatosis. [Extracted from the article]

The article discusses ten cases of 'vasculitis-like' purpuric plaques with a necrotic center that appeared after follicular unit excision (FUE) hair transplantation surgery, a phenomenon not previously described in the literature. The patients, from five trichology and hair transplantation units in Spain, experienced lesions that clinically resembled leukocytoclastic vasculitis, but all resolved spontaneously within 14 days without complications. The histopathologic study ruled out vasculitis, suggesting that trauma to blood vessels during the FUE procedure or thermal damage may have caused the lesions. The authors emphasize the importance of accurate diagnosis by dermatologists to prevent unnecessary aggressive treatments for this benign and self-resolving condition. [Extracted from the article]

This letter to the editor published in Leukemia & Lymphoma discusses a rare case of HHV8-related Castleman disease presenting with nephrotic syndrome and pauci-immune glomerulonephritis in an immunocompetent patient. The patient's condition improved with treatment, including steroids and Rituximab, leading to complete resolution of symptoms. The article highlights the challenges in diagnosing and treating this condition, emphasizing the importance of considering Castleman disease in cases of ANCA-negative pauci-immune glomerulonephritis, especially in the presence of specific symptoms. [Extracted from the article]

Mycoplasma pneumoniae is an atypical bacterium causing respiratory tract infections mainly in the pediatric population. As a superantigen, it dysregulates the immune system and promotes immunological reactions. Dermatological symptoms occur in approximately one-fourth of the patients infected with this bacterium. This review describes skin diseases occurring during Mycoplasma pneumoniae infection. Differences in the course of these diseases compared to their presentation associated with other etiological factors, are also discussed. Among the cutaneous manifestations of Mycoplasma pneumoniae infection, unspecific rashes and urticaria are the most common. This bacterium is also a frequent cause of erythema multiforme, Stevens-Johnson syndrome, Mycoplasma-induced rash and mucositis, and erythema nodosum. Less frequently toxic epidermal necrolysis, leukocytoclastic vasculitis, IgA vasculitis, subcorneal pustular dermatosis, Gianotti-Crosti syndrome, and Sweet syndrome are described. Familiarity with Mycoplasma-induced entities is important and can be useful in dermatological practice in determining the etiology and implementing appropriate treatment.

PurposeMethodsResultsConclusionWe report three cases of occlusive vasculitis following intravitreal rituximab therapy for biopsy-proven primary vitreoretinal lymphoma (PVRL), one of which was following an injection of the biosimilar Riabni (rituximab-arrx, AmGen) and two of which were following an injection of Rituxan (rituximab, Genentech).Case series.Three cases of occlusive vasculitis confirmed with fluorescein angiography are reported 5 days, 8 days, and 3.5 weeks following intravitreal injection of rituximab. The initial vision was poor (20/500, 20/150, and light perception), but vision recovered to baseline in two cases, and remained poor in the case of combined artery and vein occlusion.Occlusive vasculitis is a rarely reported but potential complication of intravitreal rituximab therapy in patients who have been previously treated with the agent and may have delayed onset. A low threshold for fluorescein angiography as a diagnostic test for post-injection vision loss and prompt treatment with topical and/or oral steroids should be considered. [ABSTRACT FROM AUTHOR]

Key Clinical Message: This pediatric case report underscores the importance of maintaining a high clinical suspicion for polyarteritis nodosa (PAN) in patients presenting with atypical features, such as migratory arthritis and subcutaneous nodules. Importantly, it highlights the focus on the potential relationship between streptococcal infection and cutaneous PAN. Early recognition and prompt, aggressive treatment is critical, as PAN can be a life‐threatening condition if left unmanaged. This case emphasizes the need for a multidisciplinary approach to effectively identify and manage this rare vasculitis disorder in the pediatric population. Polyarteritis nodosa (PAN) is a rare and life‐threatening vasculitis with diverse clinical presentations, posing a diagnostic challenge. Early recognition and prompt intervention are crucial to prevent organ damage. We present the case of an 8‐year‐old boy who exhibited atypical symptoms including migratory arthritis, myalgia, digital discoloration and ischemic changes, and subcutaneous nodules. Initial concerns for septic arthritis were ruled out. A comprehensive evaluation revealed elevated inflammatory markers and a confirmatory skin biopsy demonstrating active leukocytoclastic vasculitis, are highly suggestive of a diagnosis of PAN. Notably, elevated ASO titers suggested a possible concurrent streptococcal infection. The aggressive treatment approach with high‐dose aspirin, steroids, methotrexate, and tocilizumab is justified given the severity of the patient's symptoms and the nature of the disease process. This case underscores the importance of considering PAN in the differential diagnosis for children presenting with atypical features. Early diagnosis and prompt intervention, including addressing potential infectious triggers, are crucial for optimal outcomes in pediatric PAN. [ABSTRACT FROM AUTHOR]

As vaccinations against the SARS-CoV-2 virus have become a crucial tool in controlling the spread of the disease, reports of rare health complications have emerged, including new-onset antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAV). We systematically reviewed new-onset AAV following COVID-19 vaccination case reports and case series published in three databases before January 2024 following PRISMA guidelines to understand the characteristics of possible causal relationships or coincidences. In total, 404 articles were screened respectively by title, abstracts, and full-texts. Thirty-four papers fulfilled the inclusion criteria and have been analyzed, covering 44 patients with new-onset AAV after COVID-19 vaccination with no prior history of COVID-19 infection. Data regarding patients' metrics, comorbidities, vaccination characteristics, symptoms, diagnostics, treatment, and outcomes were investigated and summarized. The cohort consisted predominantly of females. AAV diagnosis was confirmed via biopsy, with renal dysfunction as a prevailing manifestation. In most cases, the first symptoms of AAV developed after the second dose; moreover, Pfizer-BioNTech was the most frequently administered vaccine among the analyzed cohort. Primary treatment involved glucocorticoid therapy, with a mostly favourable response. This systematic review aims to raise awareness among clinicians in the field regarding this rare but possible complication, to promote the prompt recognition and diagnosis of de novo ANCA-positive small-vessel vasculitis in timely association with SARS-CoV-2 vaccination. [ABSTRACT FROM AUTHOR]

The article presents diagnostic cases from July to December 2023. Topics include the identification and characteristics of mediastinal lymphoma in an 8-year-old Cambridge mare, the diagnosis and surgical treatment of osteomyelitis in an 11-year-old Gypsy Cob stallion, and the confirmation of Rhodococcus equi infection in a 6-week-old filly from Waikato.

X-linked lymphoproliferative disease (XLP) is a rare genetic disorder characterized by immune dysregulation. The three most common clinical phenotypes are EBV-associated infectious mononucleosis (FIM), abnormal gammaglobulinemia, and lymphoma. We present a rare case of XLP1 with neurovasculitis, which is non-EBV-related and involves multiple systems, a condition rarely seen in children. The patient initially presented with an unsteady gait, which progressively evolved into language and consciousness disorders. Additionally, CT scans revealed multiple nodules in the lungs. Subsequent genetic testing and brain tissue biopsy confirmed the diagnosis: XLP1-related cerebral vasculitis and cerebral hemorrhage. Tragically, during the diagnostic process, the child experienced a sudden cerebral hemorrhage and herniation, ultimately resulting in fatality. This case offers a comprehensive insight into XLP1-related cerebral vasculitis and cerebral hemorrhage, underscoring the significance of early diagnosis and prompt treatment, while also imparting valuable clinical experience and lessons to the medical community. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to show the increasing incidence of invasive fungal infections due to Volvariella Volvacea in patients with immunosuppression. Methods: We present a case of an invasive fungal infection caused by Volvariella volvacea, and summarize the clinical and pathological features based on this case and a review of the literature. Results: A total of seven patients with IFIs due to Volvariella Volvacea have been reported in the literature. The majority of cases have been obtained between 2019 and 2022. Including our case, they all had acquired immunosuppression. The lung and brain were the most commonly affected organs. All eight of these patients received antifungal therapy, but five still died one to seven months after occurrences of IFIs. Conclusion: The incidence of invasive fungal infections due to Volvariella Volvacea is increasing in recent years. It mainly occurred in patients with immunosuppression, especially in patients with malignant hematological cancers, and increased mortality. [ABSTRACT FROM AUTHOR]

Background: To describe high-resolution brain vessel wall MRI (VW-MRI) patterns and morphological brain findings in central nervous system (CNS) vasculitis patients. Methods: Fourteen patients with confirmed CNS Vasculitis from two tertiary centers underwent VW-MRI using a 3T scanner. The images were reviewed by two neuroradiologists to assess vessel wall enhancement characteristics and locations. Results: Fourteen patients were included (six females; average age 48 ± 19 years). Diagnoses included primary CNS vasculitis (PCNSV) in six patients and secondary CNS vasculitis (SCNSV) in eight, half of which were infection-related. Thirteen patients showed vessel wall enhancement, which was intense in eleven patients (84.6%) and concentric in twelve (92.3%), affecting the anterior circulation in nine patients (69.2%), posterior in two patients (15.4%), and both circulations in two patients (15.4%). The enhancement patterns were similar across different CNS vasculitis types. DWI changes corresponded with areas of vessel wall enhancement in 77% of patients. Conclusions: CNS vasculitis is often associated with intense, concentric vessel wall enhancement in VW-MRI, especially in the anterior circulation. The consistent presence of DWI alterations in affected territories suggests a possible link to microembolization or hypoperfusion. These imaging findings complement parenchymal brain MRI and MRA/DSA data, potentially increasing the possibility of a clinical diagnosis of CNS vasculitis. [ABSTRACT FROM AUTHOR]

Background: Exosomes have gained attention for their potential in skin rejuvenation. Currently, most exosome products are available for topical administration, and the use of subdermal injection as a route of administration has not been approved. Aims: The purpose of this case report is to describe a case of skin necrosis that occurred following an intradermal injection of lyophilized exosomes. Materials and Methods: We hereby report a case of a middle‐aged man who experienced adverse effects after receiving an intradermal injection of lyophilized exosomes. Multiple injections of an exosome product were administered to treat enlarged facial pores. Shortly after the injection, the patient felt pain and noticed several dark red bumps. Three days after injection, the lesions transformed into palpable, painful, non‐blanchable purplish papules and nodules, accompanied by central, tiny crusted erosions. The residual product was injected into the upper arm using an intradermal method. Similar lesions also appeared, and a skin biopsy showed necrotic keratinocytes, leukocytoclastic vasculitis, and eccrine necrosis. Results: There are few reports available regarding complications, especially those related to intradermal exosomes. These complications include multiple foreign‐body granulomatous reactions at the injection sites. In our case, oral prednisolone was administered for a duration of 7 days. After the treatment, the lesions exhibited notable improvement, eventually leaving post‐inflammatory hyperpigmentation. Conclusion: Utilizing exosomes through unapproved methods should be avoided due to the possibility of adverse reactions that could cause aesthetic issues. [ABSTRACT FROM AUTHOR]

Tamoxifen is a selective estrogen receptor modulator and forms the mainstay of endocrine therapy in premenopausal women with breast cancer in both adjuvant and metastatic setting. Common adverse effects are menopausal symptoms with venous thrombosis and endometrial carcinoma being rarer but more sinister complications. Vasculitis is a rarely reported reaction to tamoxifen. We report a case of a 38-year-old woman with locally advanced breast cancer, who received neoadjuvant chemotherapy followed by modified radical mastectomy and adjuvant paclitaxel. She was on maintenance tamoxifen and leuprolide for 3 months, when she presented with pruritic bilateral maculopapular rash over all her limbs, legs more than hands. A skin biopsy from the left lower limb confirmed the diagnosis of vasculitis. Tamoxifen was stopped, and patient was switched to letrozole and leuprolide. She was given antihistamines, antibiotics, fusidic acid, vitamin C, and topical steroids. The lesions resolved completely in 1 month after stoppage of tamoxifen. We report this rare side effect of tamoxifen so that oncologists can effectively diagnose and treat this distressing but reversible condition. [ABSTRACT FROM AUTHOR]

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of rare conditions predominantly affecting small vessels of skin, musculoskeletal, pulmonary, renal, and rarely central and peripheral nervous systems. Isolated neurological manifestations of AAV are uncommon and challenging to diagnose. Cocaine has been reported as a potential trigger for the development of AAV. There are only a few case reports of isolated neurological involvement in cocaine-induced AAV with poorly characterized histopathological features. We present a unique case of AAV with isolated neurological manifestations presenting with multiple cranial neuropathies, leptomeningeal enhancement on imaging and histopathologic evidence of small-vessel vasculitis in the leptomeninges and brain and extensive dural fibrosis in a patient with cocaine abuse. The patient's progressive neurological deficits were controlled after starting immunosuppression with rituximab and prednisone. We also reviewed the literature to provide the diagnostic overview of AAV and evaluate intervention options. To our knowledge, this is the first case of AAV with isolated neurological manifestations and histopathologic evidence of small-vessel vasculitis in a patient with cocaine abuse. Patients with multiple cranial neuropathies and meningeal involvement should be screened for AAV, especially if they have a history of cocaine abuse. [ABSTRACT FROM AUTHOR]

Hemophilia A and B are one of the most common hereditary bleeding disorders. Patients are predisposed to bleeding spontaneously or after minor trauma in different areas such as the skin, gastrointestinal, or joints. COVID-19 infection has been associated with various clinical manifestations and complications including rarely triggering IgA vasculitis. We report a 23-year-old man who was previously diagnosed with severe hereditary hemophilia A. He presented to our hospital with classic symptoms of IgA vasculitis, complaining of petechiae and purpura in his limbs, fatigue, body aches, poor oral intake, abdominal pain, and watery non-bloody diarrhea. He did not present with respiratory symptoms or fever typical of COVID-19 infection. Abnormal blood tests were mildly elevated C-reactive protein, elevated d-dimers, and low Factor VIII activity. Extensive immunological tests were negative. CT abdomen with contrast was unremarkable. A skin biopsy strongly indicated IgA vasculitis. COVID-19 test came back positive. The patient was managed symptomatically and with glucocorticosteroids which significantly improved his symptoms. The available literature on clinical features, laboratory tests, and management of COVID-19-associated IgA vasculitis is discussed. However, there is no case reported on the associations between hemophilia, COVID-19 infection, and IgA vasculitis. This is the first case of atypical COVID-19 infection masquerading as de novo IgA vasculitis in an adult patient with underlying hemophilia. Our case contributes to the growing body of literature about hemophilia being a possible predisposing factor that a COVID-19 virus relies on to amplify immune dysregulation resulting in IgA vasculitis. [ABSTRACT FROM AUTHOR]

Takayasu arteritis (TA) is a large-vessel vasculitis that rarely presents in infancy. Casitas B-lineage lymphoma (CBL) syndrome is a rare genetic disorder due to heterozygous CBL gene germline pathogenic variants that is characterized by a predisposition to develop juvenile myelomonocytic leukemia (JMML). Vasculitis, including TA, has been reported in several patients. Herein, we describe a patient with CBL syndrome, JMML, and TA, developing long-term remission of this vasculitis after allogeneic hematopoietic stem cell transplant (HSCT), and perform a literature review of CBL syndrome with vasculitis or vasculopathy. We report a female patient with growth delay, developmental issues, and congenital heart disease who was admitted at 14 months of age with massive splenomegaly, lymphadenopathy, fever, and hypertension. Body imaging studies revealed arterial stenosis and wall inflammation of the aorta and multiple thoracic and abdominal branches. Whole exome sequencing revealed a pathogenic variant in CBL with loss of heterozygosity in blood cells, diagnosing CBL syndrome, complicated by JMML and TA. Allogeneic HSCT induced remission of JMML and TA, permitting discontinuation of immunosuppression after 12 months. Six years later, her TA is in complete remission off therapy. A literature review identified 18 additional cases of CBL syndrome with vasculitis or vasculopathy. The pathogenesis of vasculitis in CBL syndrome appears to involve dysregulated T cell function and possibly increased angiogenesis. This case advances the understanding of vascular involvement in CBL syndrome and of the genetic, immune, and vascular interplay in TA, offering insights for treating CBL syndrome and broader TA. [ABSTRACT FROM AUTHOR]

Dialysis associated reactions presenting with urticarial vasculitis is rarely reported in medical literature. We report a 61‐year‐old gentleman who developed sudden onset dyspnea with diffuse erythema within 20 min of haemodialysis. Patient was started on Azilsartan 3 days prior to this clinical event. Labs revealed features of hemolysis and urine was positive for hemoglobinuria. All dialysis related factors responsible for this reaction were ruled out. Due to non‐resolution of skin rash, skin biopsy was attempted which revealed fibrinoid necrosis of occasional vessels with predominant lymphocytic infiltration suggestive of drug induced urticarial vasculitis. Complement levels were normal. He was managed with steroids, anti‐histaminic, discontinuation of azilsartan and change of dialyzer membrane. This case highlights a rare dermatological presentation of Type A dialysis associated reaction involving azilsartan with differential diagnosis and treatment strategies. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Although the concurrent occurrence of vasculitis with AS is uncommon, when patients diagnosed with AS exhibit symptoms including skin petechiae, purpura, abdominal discomfort, malaise, elevated ESR, and reduced complement levels, vigilant monitoring for vasculitis is advisable following the exclusion of secondary vasculitis triggers such as malignancies, infections, and pharmaceutical agents. The primary characteristic of ankylosing spondylitis (AS) involves inflammation occurring within the sacroiliac joint and the spine, leading to destruction and eventual ankylosis. A notably infrequent complication associated with AS is vasculitis, with limited reports linking AS to vasculitis. This case study documents a 48‐year‐old male, diagnosed with HLA‐B27‐positive AS for the past 15 years, who developed abdominal pain and skin lesions following the cessation of his medication on his own. Subsequent clinical evaluations identified leukocytoclastic vasculitis (LCV) related to AS after excluding all other potential causes of LCV, including drug‐related sources, cancer, hepatitis B and C viruses, Henoch‐Schönlein purpura (HSP), and IgA nephropathy. [ABSTRACT FROM AUTHOR]

Cutaneous leukocytoclastic vasculitis (LCV) is a disease thought to be related to the presence of immune complex deposition within small blood vessel walls. A 58-year-old female presented with purpuric papules on both legs, occurring concurrent with urinary symptoms. Histologically, an intraepidermal blister with luminal fragmented neutrophils was present. A dermal infiltrate was observed surrounding blood vessels; mild perivascular leukocytoclastic debris favored a diagnosis of LCV. Both direct immunofluorescence and immunohistochemistry staining also favored a diagnosis of LCV. Reactivity of the involved vessels was observed to multiple antibodies and complement, with overexpression of von Willebrand factor, CD15, and CD45. The ribosomal protein Phospho-S6 was also detected within the involved vessels, and on the blister roof and floor. The clinical triggering factor was a urinary infection that had progressed to urosepsis; the symptoms were effectively treated. We present an unusual case, where multiple immune reactions correlate with clinical and histologic changes characteristic of LCV. [ABSTRACT FROM AUTHOR]

Clinical Key Message In patients receiving anti‐TNF‐α drugs for ankylosing spondylitis, monitoring purpuric and ischemic skin lesions is crucial. This case underscores the significance of identifying and addressing drug‐induced vasculitis while stressing the necessity for prompt evaluation and exploration of alternative treatment options to safeguard patient well‐being. Abstract The case discusses a 38‐year‐old female with a history of ankylosing spondylitis (AS) who presented with skin lesions, including purpuric skin lesions and ischemia of her right foot digits, after initiating treatment with adalimumab. After excluding other potential causes, such as infections and malignancies, the patient received a diagnosis of moderate‐sized vascular vasculitis associated with adalimumab use. Discontinuation of adalimumab and treatment with high dose glucocorticoids and intravenous pulse of cyclophosphamide resulted in the resolution of her ischemic lesions. This case underscores the importance of considering drug‐related side effects in patients with new skin lesions, particularly in the context of rheumatic diseases such as AS.

This article discusses a severe case of ANCA-associated small vessel vasculitis in a 31-year-old male patient. The patient presented with various symptoms and physical manifestations of the disease. Laboratory tests and imaging studies confirmed the diagnosis of granulomatosis with polyangiitis (GPA). The patient received treatment with intravenous methylprednisolone and rituximab. The article provides information on the clinical features and treatment options for GPA. It appears to be a correspondence from Dr. Gladys Obaji, a medical professional based in Providence, RI, and may be useful for library patrons conducting research on medical topics. [Extracted from the article]

This article presents a case of Henoch-Schönlein purpura (HSP) that occurred after receiving the COVID-19 vaccine. HSP is a condition characterized by the deposition of IgA in small blood vessels, resulting in purplish skin lesions on the legs. The patient in this case also had antibodies typically associated with systemic lupus erythematosus, which is unusual for HSP. The article emphasizes the need for dermatologists to be aware of HSP even when direct immunofluorescence tests are negative, and it discusses the link between mRNA-based COVID-19 vaccines and various skin reactions, including HSP. The case underscores the importance of recognizing vaccine-related HSP and the possibility of atypical antibody profiles. [Extracted from the article]

Granulomatosis with polyangiitis (GPA) is a pauci-immune small vessel vasculitis characterised by neutrophil-mediated vasculitis and granuloma. The presence of intracranial parenchymal space-occupying lesions is rarely seen in GPA patients. In this manuscript, we report a case of GPA with granuloma of the fourth ventricle accompanied by obstructive hydrocephalus. Treatment with glucocorticoids (GCs) and multiple immunosuppressants cyclophosphamide (CYC), mycophenolate mofetil (MMF), and rituximab (RTX) showed poor efficacy in this case. After removal of the granuloma by craniotomy, GPA relapsed within 3 months. Under the premise of GC and MMF treatment combined with intrathecal injection of dexamethasone (DXM) and methotrexate (MTX), the intracranial granuloma gradually shrank, and the patient's general condition was alleviated, showing that this is an effective treatment method. Key Points • To date, there are few reports of granulomatous vasculitis combined with granuloma of the fourth ventricle, and our case is the second. • In this case, multiple immunosuppressants and rituximab were ineffective treatments, and the intracranial granuloma was effectively controlled by intrathecal injection of dexamethasone (DXM) and methotrexate (MTX). • Based on this report, it can be suggested that intrathecal injection is effective in treating patients with GPA and central nervous system involvement, but large-scale sample studies are needed. [ABSTRACT FROM AUTHOR]

Myeloperoxidase (MPO) is a pro-oxidant enzyme mainly found in the azurophilic granules of neutrophils. It not only displays a key role in the intracellular microbial killing process but also contributes to the extracellular clearance of several pathogens. This study aimed to detect MPO in cutaneous leukocytoclastic vasculitis (LCV) using immunohistochemistry. We retrospectively collected 22 confirmed cases of skin LCV diagnosed in our pathology department over 11 years (2012–2023). Immunohistochemistry was performed using anti-myeloperoxidase antibody (Leica clone 59A5) on the LeicaBond MAX automated system, following manufacturer's instructions. Two pathologists assessed immunohistochemical staining, scoring intensity as weak (+), moderate (++), or strong (+++). Patients' mean age was 56.9 years, with a male-to-female ratio of 1.18. Pathologically, vasculitis involved small blood vessels in all cases. Immunohistochemical analysis showed granular positive MPO staining in 59.1% of cases. Staining intensity was weak in 46.15%, moderate in 46.15%, and strong in 7.69%. Staining was patchy in 84.62% and diffuse in 15.38% of cases. MPO expression, detected in 59.1% of cutaneous LCV tissues, exhibited a patchy and peri-vascular distribution. It holds potential as a diagnostic marker for patients with early or minor histological changes. [ABSTRACT FROM AUTHOR]

Introduction: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may trigger autoimmune disease (AD) through initial innate immune activation with subsequent aberrations in adaptive immune cells leading to AD. While there are multiple reports of incident AD diagnosed after COVID-19, the risk in the context of key circulating strains is unknown. Methods: TriNetX, a global, federated, health research network providing access to electronic medical records across 74 healthcare organizations, was utilized to define an adult cohort between January 1, 2020, and March 3, 2023. Exposure was defined as COVID-19 diagnosis (ICD-10 code or positive laboratory test). Age- and sex-propensity score-matched controls never had COVID-19 diagnosed. Outcomes were assessed 1 month to 1 year after the index date. Patients with AD prior to or within 1 month after the index date were excluded from the primary analysis. Incidence and risk ratios of each AD were assessed. Results: A total of 3,908,592 patients were included. Of 24 AD patients assessed, adjusted risk ratios for eight AD patients who had COVID-19 were higher compared to those who had no COVID-19. Cutaneous vasculitis (adjusted hazard ratio (aHR): 1.82; 95% CI 1.55-2.13), polyarteritis nodosa (aHR: 1.76; 95% CI 1.15-2.70), and hypersensitivity angiitis (aHR: 1.64; 95% CI 1.12-2.38) had the highest risk ratios. Overall, psoriasis (0.15%), rheumatoid arthritis (0.14%), and type 1 diabetes (0.13%) had the highest incidence during the study period, and of these, psoriasis and diabetes were more likely after COVID-19. The risk of any AD was lower if COVID-19 was diagnosed when Omicron variants were the predominant circulating strains. A positive antinuclear antibody was more likely and predictive of AD after COVID-19. Discussion: SARS-CoV-2 may be a potential trigger for some AD, but the risk for AD may decrease with time given the apparent lower risk after infection with Omicron variants. [ABSTRACT FROM AUTHOR]