Search

Primary angiitis of central nervous system (PACNS) is a rare idiopathic vasculitis that typically involves small arteries. An 18-year-old woman was operated on for resection of a ruptured aneurysm in a cerebral artery. Multiple aneurysms of cerebral arteries had been detected by neuroimaging examinations since the age of 12, and she had been administered drugs following a diagnosis of PACNS since the age of 15. The resected aneurysm was a ruptured saccular aneurysm occurring in a medium-sized artery. Histologically, necrotizing arteritis of the polyarteritis nodosa (PAN) type was noted in the aneurysmal wall. It consisted of an admixture of acute and healing stages. In the acute stage, fibrinoid necrosis in the intima and media and intense inflammatory cell infiltrate in the entire wall were present. The inflammatory cells mainly consisted of lymphocytes, including plasma cells, neutrophils, and macrophages. In the healing stage, disappearance of fibrinoid necrosis, fibrosis in the intima and media, and scarce inflammatory cells were noted. The acute stage was mainly present near the ruptured site. From these findings, the aneurysm was considered to have been caused by necrotizing arteritis of the PAN type. Although saccular aneurysmal formation in a medium-sized artery is rare in PACNS, an understanding of aneurysms produced by necrotizing arteritis of the PAN type offers useful information for the diagnosis and treatment of PACNS., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The purpose of the article: Polyarteritis nodosa (PAN) is a rare systemic necrotizing vasculitis preferentially targeting medium-sized arteries. PAN has two clinical entities: systemic PAN (sPAN) and cutaneous PAN (cPAN). cPAN is a skin-limited vasculitis, while ulcerative cPAN often predicts a higher risk of recurrence and a worse prognosis. However, there is still little experience and no consensus on cPAN treatment. Janus kinase-signal transducer and activator of transcription (JAK-STAT) inhibition with baricitinib (JAK1/JAK2) inhibitor in patients with inflammatory skin diseases has demonstrated good therapeutic outcomes in several clinical studies. However, the use of baricitinib in patients with cPAN has not been reported to date., Materials and methods: We report the first case of cPAN successfully treated with baricitinib. The patient had previously undergone various treatments, including corticosteroids and immunosuppressants, but these were continually switched due to inadequate efficacy or significant side effects., Results: Following treatment with baricitinib, the patient's ulcers healed, subcutaneous nodules resolved, and livedo reticularis alleviated, resulting in a marked improvement in quality of life. No severe adverse reactions were observed during the treatment period. Over 1 year of follow-up, there was no recurrence of the rash., Conclusions: Our results support the evidence that baricitinib is a promising therapy for cPAN.

Background: Photoacoustic microscopy is expected to have clinical applications as a noninvasive and three-dimensional (3D) method of observing intradermal structures., Objective: Investigate the applicability of a photoacoustic microscope equipped with two types of pulsed lasers that can simultaneously recognize hemoglobin and melanin., Methods: 16 skin lesions including erythema, pigmented lesions, vitiligo and purpura, were analyzed to visualize 3D structure of melanin granule distribution and dermal blood vessels. 13 cases of livedo racemosa in cutaneous polyarteritis nodosa (cPN) were further analyzed to visualize the 3D structure of dermal blood vessels in detail. Vascular structure was also analyzed in the biopsy specimens obtained from tender indurated erythema of cPN by CD34 immunostaining., Results: Hemoglobin-recognition signal clearly visualized the 3D structure of dermal blood vessels and melanin-recognition signal was consistently reduced in vitiligo. In livedo racemosa, the hemoglobin-recognition signal revealed a relatively thick and large reticular structure in the deeper layers that became denser and finer toward the upper layers. The numerical analysis revealed that the number of dermal blood vessels was 1.29-fold higher (p<0.05) in the deeper region of the lesion than that of normal skin. The CD34 immunohistochemical analysis in tender indurated erythema revealed an increased number of dermal vessels compared with normal skin in 88.9% (8/9) of the cases, suggesting that vascular network remodeling had occurred in cPN., Conclusion: The photoacoustic system has an advantage in noninvasively detecting dermal blood vessel structures that are difficult to recognize by two-dimensional histopathology specimen examination and is worth evaluating in various skin diseases., Competing Interests: Conflicts of Interest None declared., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: Patients with systemic vasculitis may develop myalgia as an initial symptom. However, the immunopathology of vasculitic myopathy remains unclear. We investigated the immunopathological features of skeletal muscle in small-to-medium-sized vessel vasculitis., Methods: We analysed muscle tissue biopsies from 15 patients with vasculitis, including antineutrophil cytoplasmic antibodyassociated vasculitis and polyarteritis nodosa, and 15 patients with autoimmune myositis (AIM), including polymyositis and immune-mediated necrotising myopathy, as comparison disease controls. Immunohistochemical staining for CD56/neural cell adhesion molecule (NCAM), major histocompatibility complex class I, C5b-9/membrane attack complex (MAC), and CD31 was performed. The vascularity score was defined as the total number of CD31-expressing blood vessels. The association between CD56/NCAM-expressing myofibers and clinical findings was evaluated in patients with vasculitis., Results: Patients with vasculitis had a significantly lower frequency of CD56/NCAM-expressing myofibers than those with AIM and a positive correlation between the frequency of CD56/NCAM-expressing myofibers and serum aldolase levels. Patients with vasculitis had significantly fewer major histocompatibility complex class I-expressing myofibers and C5b-9/MAC deposits on the sarcolemma than those with AIM. C5b-9/MAC deposits in blood vessels were observed in >70% of patients with vasculitis. Patients with vasculitis had significantly higher vascularity scores in the endomysium than those with AIM., Conclusions: Patients with vasculitis demonstrated mild myofiber damage based on the lower involvement of CD56/NCAM-expressing myofibers compared to those with AIM. Complement component deposits on the vessel walls and hypervascularity in the endomysium areas may be immunopathological features of vasculitic myopathy.

The ongoing debate on whether lymphocytic thrombophilic arteritis (LTA) is a separate disease or a type of polyarteritis nodosa (PAN) has yet to be settled. In this study, we analyzed the nature of infiltrating cells in LTA to resolve this controversy. Skin biopsies from five female patients (mean age 29.4 years, age range 16-45 years) diagnosed with LTA were immunostained for CD3, CD20, CD68, lysozyme, myeloid cell nuclear differentiation antigen, myeloperoxidase, and PU.1. Immunohistochemistry revealed that the majority of mononuclear cells in all five cases were not lymphocytes but myelomonocytic cells. Given that the infiltrating cells are of the myelomonocyte lineage including immature myeloid cells, PAN was deemed the more appropriate diagnosis for the five cases rather than LTA. Whether PAN with immature myeloid cells (histiocytoid PAN) is the same disease as conventional PAN with mature neutrophils requires further investigation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Blood vessels are indispensable for host survival and are protected from inappropriate inflammation by immune privilege. This protection is lost in patients with autoimmune vasculitides, a heterogeneous group of diseases causing damage to arteries, arterioles, and capillaries. Vasculitis leads to vascular wall destruction and/or luminal occlusion, resulting in hemorrhage and tissue ischemia. Failure in the quantity and quality of immunosuppressive regulatory T cells (Treg) has been implicated in the breakdown of the vascular immune privilege. Emerging data suggest that Treg deficiencies are disease-specific, affecting distinct pathways in distinct vasculitides. Mechanistic studies have identified faulty CD8 + Tregs in Giant Cell Arteritis (GCA), a vasculitis of the aorta and the large aortic branch vessels. Specifically, aberrant signaling through the NOTCH4 receptor expressed on CD8 + Treg cells leads to rerouting of intracellular vesicle trafficking and failure in the release of immunosuppressive exosomes, ultimately boosting inflammatory attack to medium and large arteries. In Kawasaki's disease, a medium vessel vasculitis targeting the coronary arteries, aberrant expression of miR-155 and dysregulated STAT5 signaling have been implicated in undermining CD4 + Treg function. Explorations of mechanisms leading to insufficient immunosuppression and uncontrolled vascular inflammation hold the promise to discover novel therapeutic interventions that could potentially restore the immune privilege of blood vessels and pave the way for urgently needed innovations in vasculitis management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jin, Parreau, Warrington, Koster, Berry, Goronzy and Weyand.)

IgA vasculitis (IgAV) is the most frequent form of vasculitis in childhood which classically presents with purpura of the lower extremities, joint pain or swelling and abdominal pain. Though it is a self-limiting disease, and its prognosis is generally good, glomerulonephritis is one of the most important complications. IgAV is classified as a small vessel vasculitis, and though glomerulonephritis develops in IgAV, necrotizing arteritis is rarely seen. Here, we present a case of a 13-year-old girl with IgAV, glomerulonephritis, and necrotizing arteritis in the small renal arteries. There have been only a few reports of adult cases of IgAV with necrotizing arteritis in the kidneys, but there have been no pediatric cases. Some previous reports showed a high mortality rate and implied the possibility of overlap with other vasculitides. In the current report, a rare case of IgAV is described which exhibited necrotizing arteritis rather than overlap with another vasculitis, with a relatively typical clinical course for IgAV and laboratory tests., (© 2021. Japanese Society of Nephrology.)

Childhood-onset polyarteritis nodosa (PAN) is a rare and systemic necrotising vasculitis in children affecting small- to medium-sized arteries. To date, there have been only a few reports because of its rarity. Thus, we aimed to investigate the clinical manifestations, laboratory findings, treatment, and long-term outcomes in patients with childhood-onset PAN and to evaluate the usefulness of the paediatric vasculitis activity score (PVAS). We retrospectively analysed the data of nine patients with childhood-onset PAN from March 2003 to February 2020. The median ages at symptom onset, diagnosis, and follow-up duration were 7.6 (3-17.5), 7.7 (3.5-17.6), and 7.0 (1.6-16.3) years, respectively. All patients had constitutional symptoms and skin manifestations, while five exhibited Raynaud's phenomenon. Organ involvement was observed in one patient. The median PVAS at diagnosis was 7 (range: 2-32). Prednisolone was initially used for induction in all patients, and other drugs were added in cases refractory to prednisolone. All patients survived, but three patients with high PVAS at diagnosis experienced irreversible sequelae, including intracranial haemorrhage and digital amputation. In conclusion, early diagnosis and treatment may minimise sequelae in patients with childhood-onset PAN. This study suggests that high PVAS score at diagnosis may be associated with poor prognosis.

Polyarteritis nodosa (PAN) is a necrotizing vasculitis. The clinical manifestations are determined by the location of the compromised arteries. Cutaneous PAN can present as nodular lesions similar to erythema nodosum, palpable purpura, livedo reticularis, and ulceration. It often affects the lower limbs but other anatomical sites can also be involved. However, concomitant facial edema is an extremely rare manifestation. It has been more than 20 years since the last case report describing this unusual presentation of PAN. Furthermore, our patient is the first case presenting with hemifacial edema fluctuating every second or third day due to PAN confirmed by skin biopsy., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Lymphocytic thrombophilic arteritis (LTA), or macular lymphocytic arteritis, is defined by a primary lymphocytic vasculitis. However, the nosology of LTA has been controversial, with speculation that it may represent an indolent non-nodule-forming variant of cutaneous polyarteritis nodosa (cPAN)., Objective: This study compares the clinicopathologic features of patients with LTA or cPAN to assess if these conditions should be considered distinct entities., Methods: This is a cross-sectional study of all LTA and cPAN cases at a single tertiary center using prospectively collected clinical data and blinded histologic assessment., Results: The study included 17 patients with LTA and 13 patients with cPAN. Clinically, cases of LTA were distinguished by a more widespread pattern of livedo racemosa, which was noninfiltrated and asymptomatic. In contrast, cPAN was associated with localized starburst livedo, purpura, and episodic features including nodules, pain, and large inflammatory ulcers. When patients were separated according to the presence (>5%) or paucity (≤5%) of neutrophils on blinded histology review, they had distinct clinical features and differences in disease course., Limitations: This was a single-center study., Conclusion: Our data support the classification of LTA and cPAN as separate entities rather than a spectrum of the same disorder and highlight the importance of clinicopathologic correlation in distinguishing these conditions., (Copyright © 2019 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

The etiology of polyarteritis nodosa (PAN) and localized PAN, including cutaneous arteritis (CA), remains unknown; however, initial endothelial damage has been implicated. The intima of the vasculitis lesions is predominantly infiltrated by innate-like bystander-activated CD8 T cells, in addition to the macrophages. Macrophages are among the major inflammatory cells involved in innate immunity and are classified into M1 and M2 subtypes. M1-type macrophages kill pathogens and cause inflammation, while M2-type macrophages promote the repair of tissues. Macrophage subtypes infiltrating in PAN and localized PAN vasculitis lesions have not yet been investigated. Innate immune response to a triggering factor on the endothelial cell surface may initiate CA pathogenesis. Thus, many M1-type macrophages may infiltrate in the intima during early CA. We assessed this hypothesis by immunohistochemical observation of macrophage phenotypes and polarization. Twenty-seven skin biopsy specimens from patients with CA were retrieved. Based on histology, we classified CA into four phases. The phenotypes of infiltrating macrophages in CA were evaluated by immunohistochemistry using antibodies against Iba-1, a pan-macrophage marker, and CD163, an M2-type macrophage marker. Our results showed that the ratio of CD163-positive M2-type macrophages to Iba1-positive macrophages was lower in the intima in the early stage of CA than in the later stage. In the media to adventitia, there was no significant difference in the ratios between these stages. These findings indicate that innate immunity is involved in the intima in the early stage of CA, suggesting that a trigger for CA might exist in endothelial cells.

We developed a questionnaire to examine the findings of cutaneous arteritis among dermatological specialists experienced in vasculitis as certified by the Committee for guidelines for the management of vasculitis and vascular disorders of the Japanese Dermatological Association. We sent a questionnaire to 12 dermatological facilities identified through the revised Committee for guidelines for the management of vasculitis and vascular disorders of the Japanese Dermatological Association. Retrospective data obtained from 84 patients at the 12 dermatological facilities between 2012 January 2016 December were evaluated. The 84 patients were categorized into two groups, a systemic steroid treatment group (group 1, n = 52) and a no systemic steroid treatment group (group 2, n = 32). C-reactive protein in group 1 patients was significantly higher than that in group 2 patients. Frequency of fever, arthritis, myalgia- and peripheral neuropathy in group 1 was significantly higher than that in group 2. We propose that these symptoms could serve as early markers for the transfer from cutaneous arteritis to systemic polyarteritis nodosa. We further suggest that patients who are subsequently associated with cerebral hemorrhage and infarction, who are originally diagnosed as having cutaneous arteritis, could progress to systemic polyarteritis nodosa. The study demonstrated that it is important for dermatologists to detect these findings early in order to establish an accurate diagnosis and a timely treatment., (© 2020 Japanese Dermatological Association.)

This report presents a novel canine condition in 32 dogs in which aberrant migration of Spirocerca lupi larvae through mesenteric arteries, instead of gastric arteries, led to small or large intestinal infarction. This form of spirocercosis was first recognized in Israel in 2013 and is currently ongoing. Typical clinical signs were anorexia and weakness of 3 to 4 days and, less frequently, vomiting and diarrhea, followed by collapse, bloody diarrhea, and severe vomiting. Exploratory laparotomy showed 1 or more infarcted and often perforated intestinal segments in all cases. Microscopically, there was intestinal mucosal to transmural coagulative necrosis and mesenteric multifocal necrotizing eosinophilic arteritis, thrombosis, hemorrhage, and early fibroplasia. Third-stage S. lupi larvae were identified by morphologic features in 9 of 32 (28%) cases, and the species was confirmed by polymerase chain reaction in 4 cases. Nearly 50% of the dogs had been receiving prophylactic therapy, which did not prevent this form of spirocercosis.

Background: Macular lymphocytic arteritis most commonly presents as hyperpigmented macules on the lower limbs. The pathogenesis of this disease is still unclear and there is an ongoing debate regarding whether it represents a new form of cutaneous vasculitis or an indolent form of cutaneous polyarteritis nodosa., Objective: To describe clinical, histopathological, and laboratory findings of patients with the diagnosis of macular lymphocytic arteritis., Methods: A retrospective search was conducted by reviewing cases followed at the Vasculitis Clinic of the Dermatology Department, School of Medicine, University of São Paulo, between 2005 and 2017. Seven patients were included., Results: All cases were female, aged 9-46 years, and had hyperpigmented macules mainly on the legs. Three patients reported symptoms. Skin biopsies evidencing a predominantly lymphocytic infiltrate affecting arterioles at the dermal subcutaneous junction were found, as well as a typical luminal fibrin ring. None of the patients developed necrotic ulcers, neurological damage, or systemic manifestations. The follow-up ranged from 18 to 151 months, with a mean duration of 79 months., Study Limitations: This study is subject to a number of limitations: small sample of patients, besides having a retrospective and uncontrolled study design., Conclusions: To the best of the authors' knowledge, this series presents the longest duration of follow-up reported to date. During this period, none of the patients showed resolution of the lesions despite treatment, nor did any progress to systemic vasculitis. Similarities between clinical and skin biopsy findings support the hypothesis that macular lymphocytic arteritis is a benign, incomplete, and less aggressive form of cutaneous polyarteritis nodosa., (Copyright © 2019 Sociedade Brasileira de Dermatologia. Published by Elsevier España, S.L.U. All rights reserved.)

Introduction: Excoriation (skin picking) disorder is included in the DSM-5 in the obsessive compulsive and related disorders category. It is defined as the recurrent urge to touch, scratch, scrape, scrub, rub, squeeze, bite or dig in the skin, leading to skin lesions. It is a rare disorder (1.4-5.4% of the population) and occurs mainly in women., Case Report: this article reports the case of a 31-year-old female patient, initially assessed by dermatology and orthopaedics for the presence of infected ulcerated lesions on her lower limbs, with other superficial lesions from scratching on her chest, arms, forearms, back and head. The patient also reported symptoms of anxiety, so was assessed by consultation-liaison psychiatry., Discussion: skin picking, normal behaviour in mammals, becomes pathological from a psychiatric point of view when it is repetitive and persistent, as in the case of excoriation disorder. In view of the reported relationship with the obsessive-compulsive spectrum, use of selective serotonin reuptake inhibitors and cognitive behavioural therapy are recommended., (Copyright © 2018. Publicado por Elsevier España, S.L.U.)

Systemic vasculitis involving the breast is a rare clinical condition and may mimic breast cancer or mastitis clinically or radiographically. Here, we report a case of polyarteritis nodosa (PAN) with breast involvement and perform a literature review of published cases of systemic vasculitis affecting the breast to better understand this disorder. We report a case of PAN affecting the right breast in a young woman. A retrospective review was performed by searching Medline, Embase, Web of Science, the Cochrane Library, and Scopus for cases of systemic vasculitis involving the breast written in English up to June 1st, 2018. A 27-year-old woman presented with a painful mass in the right breast was diagnosed as PAN by the biopsy. She was treated with prednisone and methotrexate for 6 months, at which time her condition had stabilized and inflammatory markers had normalized. A total of 66 cases were identified, with granulomatosis with polyangiitis (GPA), giant cell arteritis (GCA), and PAN as the main types. The typical manifestation was mass (79.2%, 53/67) in the breast, and all diagnoses were made by the pathology of the breast biopsy. Glucocorticoid and immunosuppressant were the main therapies, and 74.6% (50/67) patients achieved remission during follow-up. Our case and a literature review of 66 cases of systemic vasculitis involving the breast reveal the importance of tissue biopsy to obtain a definitive diagnosis, because the vasculitis subtype strongly influences prognosis.

The panniculitides remain as one of the most challenging areas for clinicians, as they comprise a heterogeneous group of inflammatory diseases involving the subcutaneous fat with potentially-shared clinical and histopathological features. Clinically, most panniculitides present as red edematous nodules or plaques. Therefore, in addition to a detailed clinical history, a large scalpel biopsy of a recent-stage lesion with adequate representation of the subcutaneous tissue is essential to specific diagnosis and appropriate clinical management. Herein we review the panniculitides of particular interest to the rheumatologist.

Background: Polyarteritis nodosa is a small vessel to medium vessel vasculitis that frequently presents with multi-organ involvement, but can sometimes be limited to single organs such as the testes. Patients often require treatment with glucocorticoids, plus or minus additional immunosuppressive therapy depending on the severity of the disease. We describe a rare case of polyarteritis nodosa involving the right testis and urinary bladder without other systemic features of vasculitis., Case Presentation: A previously healthy 54-year-old First Nations Canadian man presented with intermittent gross hematuria. He underwent surgical excision of his right testis for cryptorchidism and a transurethral resection of a bladder mass. Histology showed an active medium vessel vasculitis in both organs. On extensive clinical, laboratory, and radiographic review, he had no systemic features of vasculitis. On 2-year follow-up, he has not required any systemic therapy and has not developed further symptoms., Conclusion: Single organ polyarteritis nodosa can sometimes be managed with surgical excision of the involved organ alone. Although our patient had two organs involved, we extrapolated the results of our literature search to guide his care. This case highlights the potential for surgical excision to cure polyarteritis nodosa despite the involvement of two organs in the absence of symptoms and signs of systemic vasculitis.

Coronary arteritis is an uncommon cause of sudden death in non-atherosclerotic coronary diseases, and is mostly associated with systemic vasculitis or systemic autoimmune diseases; therefore, sudden death due to isolated coronary arteritis rarely occurs. The case described in this report is that of a 34-year-old man with no significant personal medical history who died suddenly after presenting with nausea. Postmortem examination revealed a significant infiltration of lymphocytes predominantly on the adventitia and periadventitial tissues of the coronary arteries in the epicardium. The lymphocytic infiltrate partially extended to the thickened intima with fibrosis, destructing the media and internal elastic lamina, and the lumen was occluded by a thrombus in the left main stem and left anterior descending branch. The arterial walls exhibited focal fibrinoid necrosis with regression in the intima and fibrous scars with angiogenesis in the media and adventitia. Focal myocardial infarction was detected in the left ventricle as a fibrotic change of the myocardium. No findings associated with vasculitis were discerned in the aorta, other peripheral arteries, or major organs. Laboratory tests of postmortem blood samples returned negative results for antinuclear antibodies, cryoglobulin, immunoglobulin G4, and cytoplasmic anti-neutrophil cytoplasmic antibodies for myeloperoxidase and proteinase 3. These autopsy findings suggest that the sudden death was caused by isolated necrotizing vasculitis that is assumed to be polyarteritis nodosa localized at the coronary arteries. However, pathological characteristics may not be exactly the same between isolated necrotizing vasculitis in the coronary arteries and polyarteritis nodosa.

Polyarteritis nodosa is a progressive, often life-threatening, vasculitis affecting multiple organs, including the skin and peripheral nerves. We report a patient presenting with systemic features of the disease and with characteristic lesions in the feet 3 weeks after vaccination against hepatitis B virus infection.

Polyarteritis nodosa (PAN) is a necrotizing vasculitis affecting medium-sized vessels whose main manifestations are weight loss, fever, peripheral neuropathy, renal, musculoskeletal, gastrointestinal tract and/or cutaneous involvement(s), hypertension and/or cardiac failure. Peripheral neuropathy is one of the most frequent and earliest symptoms, affecting 50% to 75% of PAN patients. Central nervous system involvement affects only 2% to 10% of PAN patients, often late during the disease course. Treatment relies on combining corticosteroids and an immunosuppressant (mainly cyclophosphamide) in patients with poor prognoses. In patients with hepatitis B virus-related PAN, plasma exchanges and antiviral drugs should be combined with corticosteroids., (Copyright © 2019 Elsevier Inc. All rights reserved.)

There is a need for better definition of polyarteritis nodosa (PAN) subphenotypes and the influence of ethnicity and geography. This study is aimed to study the demographic and clinical features of PAN cohorts from the UK and Turkey (TR) and to compare and contrast disease characteristics. A retrospective survey of databases from two vasculitis centres between 1990 and 2016 for PAN patients fulfilling the EMEA Vasculitis Classification algorithm. All paediatric-onset adult patients met the Ankara 2008 (EULAR/PReS endorsed) criteria for childhood PAN. Those with typical angiographic and/or histopathologic findings consistent with PAN were included. 93 (M/F: 51/42) patients (UK: 47, TR: 46) were included. Three were HBV-related, 20 (21.5%) had paediatric onset and 16 (16.5%), cutaneous PAN. TR patients had younger age of disease onset 44 (28.5-59.0) vs. 24.5 (11.8-40.5), p = 0.002. Twelve (26%) of TR patients had monogenic disease (Familial Mediterranean Fever association (n = 7), deficiency of adenosine deaminase 2, DADA2, (n = 5). No difference was found in phenotype between paediatric and adult onset patients except for frequency of cutaneous lesions (p = 0.002). During a median 67.5 (32-126) months follow-up, 13 patients died (12.7% in UK vs. 15.2% in Turkish cohorts). No difference was found between two cohorts in relation to relapse rate, death and vasculitis damage index. This study defined a diagnosis of PAN according to the EMEA algorithm. The TR group had a younger age of disease onset and more cases of monogenic disease; however, disease extent, relapse rate, damage index and death rates were similar between groups.

Polyarteritis nodosa (PAN), a systemic necrotizing vasculitis with multiorgan development, is generally restricted to the medium-sized muscular arteries. The varied initial clinical presentations of PAN can lead to a delayed diagnosis. We present the case of a middle-aged male patient who presented with an acute onset right-sided testicular pain as the initial clinical symptom with ischemic changes on ultrasonogram, thereby requiring orchiectomy. This was reported to be a case of tubercular epididymo-orchitis. On review, the biopsy revealed features of necrotizing arteritis as seen in PAN with fibrinoid necrosis and giant cells, thus highlighting the fact that vasculitis due to PAN may have a localized presentation at the time of diagnosis. PAN should be distinguished from other causes of epididymo-orchitis and other vasculitis lesions, the most common being tubercular etiology in the Asian population., Competing Interests: There is no conflict of interest

Aims: Interobserver reliability of histopathological features in differentiation between cutaneous polyarteritis nodosa (cPAN) and superficial thrombophlebitis (ST) by assessment of inter-rater agreement of five histological features was investigated., Methods and Results: All sections of cPAN and ST were evaluated independently by three experienced pathologists and one resident of pathology. The histopathological features studied included elastic fibre distribution in the vascular wall, a smooth muscle arrangement pattern, an internal elastic lamina pattern, fibrinoid necrosis and luminal thrombosis. Agreement analysis was performed using the kappa coefficient. Sensitivity, specificity, positive predictive value (PPV), positive likelihood ratio (PLR) and 95% confidence interval (95% CI) of the useful histopathological features were analysed. Of all 62 biopsies, 28 were cPAN and 34 were ST. Reproducibility between four observers was in substantial agreement (κ = 0.73). Elastic fibre distribution in the vascular wall (κ = 0.68), fibrinoid necrosis (κ = 0.63), an internal elastic lamina pattern (κ = 0.51) and a smooth muscle arrangement pattern (κ = 0.46) showed high specificity and PPV for differentiating between cPAN and ST. The smooth muscle arrangement pattern, internal elastic lamina pattern and elastic fibre distribution in the vascular wall may be obscured when extensive inflammation and necrosis occurs., Conclusions: These aforementioned histopathological features are useful in differentiation between cPAN and ST. The Verhoeff-van Gieson (VVG) elastic stain is an important histochemical study for differentiating between cPAN and ST, particularly in cases with extensive inflammation and necrosis., (© 2018 John Wiley & Sons Ltd.)

Polyarteritis nodosa (PAN) is a rare vasculitis affecting medium-sized vessels. Cutaneous PAN is a clinical variant, and we report the first case of empagliflozin-induced cutaneous PAN in a 69-year-old man. After starting empagliflozin, the patient presented with tender subcutaneous nodules on his legs, which showed a medium-sized vessel vasculitis on histopathology. Upon cessation of this medication, he had full resolution of these nodules. This case illustrates that empagliflozin can induce cutaneous PAN, and further attention to this medication's association with cutaneous PAN is warranted.

The etiology of polyarteritis nodosa (PAN) and localized PAN is still unknown, although a T cell-mediated immune mechanism has been considered. CD8 T cells participate not only in the antigen-dependent adaptive immune system, but also in the antigen-independent innate immune system. Non-antigen-activated CD8 T cells express a unique phenotype: granzyme B (GrB) positive /CD25 negative /programmed death-1 (PD-1) negative. The aims of this study were to assess the participation of T cells, especially innate CD8 T cells, in the development of vasculitis. Twenty-eight consecutive cases of skin biopsy specimens with cutaneous vasculitis of small muscular arteries (CVSMA) were retrieved. The series comprises of 21 cases of cutaneous arteritis, three cases of PAN, and four cases of rheumatoid vasculitis. Cases of antineutrophil cytoplasmic antibody-associated vasculitis were excluded. The phenotypes of infiltrating lymphocytes in vasculitis lesions were evaluated by immunohistochemistry. In most cases of CVSMA, the number of CD8 T cells infiltrating the intima was higher than that of CD4 T cells, and significant numbers of GrB-positive cells, which represent activated CD8 T cells, were observed. However, GrB/CD25-double-positive cells, which correspond to antigen-activated T cells, were very few in a small number of cases. Cells positive for PD-1, which is also expressed on antigen-activated CD8 T cells, were not detected. We conclude that a T cell-mediated immune mechanism, involving cytotoxic CD8 T cells, may play a role in the development of CVSMA. Low expression of CD25 in activated CD8 T cells suggests that activation was antigen-independent.

Arteritis/polyarteritis occurs spontaneously in many species used in preclinical toxicology studies. In Göttingen minipigs, arteritis/polyarteritis is an occasionally observed background change. In the minipig, this finding differs in frequency and nature from age-related polyarteritis nodosa in rats or monkeys, and Beagle pain syndrome in dogs. In minipigs, it can be present in a single small- or medium-sized artery of an organ or a few organs and is most commonly recorded in the cardiac and extracardiac blood vessels, vagina, oviduct, rectum, epididymis, spinal cord, pancreas, urinary bladder, kidneys, and stomach. The etiology is unknown although it has been considered in minipigs as well as in rats, dogs, and monkeys to be possibly immune mediated. This background change is important with respect to its nature and distribution in the minipig in order to distinguish it from drug-induced vascular changes, which might occur in similar locations and have similar morphologic features. This review summarizes the morphology, incidence, and predilection sites of arteritis as a spontaneously occurring background change and as a drug-induced vasculopathy in the minipig, and also describes the main aspects to consider when evaluating vascular changes in Göttingen minipig toxicity studies and their human relevance.

Cutaneous polyarteritis nodosa is a rare disease that affects vessels of the deep skin and the subcutaneous tissue. Its etiopathology remains unknown. It predominantly affects skin, and the main cutaneous symptoms are subcutaneous nodules, livedo reticularis, and ulcerations that are mainly located on legs. Cutaneous polyarteritis nodosa can also cause extracutaneous symptoms (fever, malaise, myalgias, arthralgias, neuropathy). It is a chronic benign disease with a relapsing course. Diagnostic criteria for this disease were recently proposed and both clinical and typical histological features must be present to confirm the diagnosis. Treatment of cutaneous polyarteritis nodosa depends on the severity of the disease and the frequency of relapses. Mild forms limited to skin lesions should be treated with nonsteroidal anti-inflammatory drugs, colchicine and locally applied glucocorticosteroids. Cases that are refractory to the treatment, that recur with extracutaneous symptoms may require applying more aggressive approach (glucocorticosteroids orally, hydroxychloroquine, azathioprine, methotrexate, mycophenolate mofetil or intravenous immunoglobulins). The prognosis in cutaneous polyarteritis nodosa is favorable and the disease rarely turns into a systemic form.

Cogan's syndrome (CS) is defined by the combination of hearing loss, vertigo, and ocular inflammation of uncertain cause, and can be associated with variable vessel vasculitis. Vasculitic manifestations may include arteritis (affecting large, medium or small arteries), aortitis, and aortic and mitral valvulitis. Cutaneous manifestations including erythema, papules, subcutaneous nodules, and purpura sometimes occur; however, to date, only six cases have been histologically confirmed to have genuine vasculitis. Here, we report two cases of CS, one of which involved a patient who developed the typical symptoms of Takayasu arteritis and purpuric lesions in the legs, with histologic findings consistent with small vessel vaculitis in the dermis. The second case involved a patient who developed subcutaneous nodules in the legs and the axilla, and histologic findings revealed a necrotizing vasculitis of the small arteries in the interlobular area. Both cases were successfully treated with systemic steroid therapy. Based on the clinical features and the examination data, there is a possibility that a Chlamydia trachomatis infection played a pivotal role in the pathogenesis of those vasculitides.

Kawasaki disease (KD) is the commonest vasculitic syndrome. It affects medium-sized arteries, principally the coronary arteries. Histologically, coronary arteritis begins at 6 to 8 days after the onset of KD and the inflammation rapidly involves all layers of the artery. This results in severe damage to the structural components of the artery leading to arterial dilation. The inflammatory infiltrate in KD arteritis is characterized predominantly by infiltration of monocytes and macrophages. Activated neutrophils, monocytes and macrophages are believed to be involved in the initial stage of coronary arteritis. Inflammatory cell infiltration may continue for up to 25 days of disease following which the inflammatory cells gradually decline in number. Inflammatory lesions in the arteries are relatively synchronous as they evolve from an acute to the chronic stage. If a giant aneurysm remains or vessel recanalization occurs after thrombotic occlusion of an aneurysm, the remodeling of vascular structures may continue for a much longer time., (© 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Muscular involvement is common during systemic vasculitides, such as polyarteritis nodosa. However, in rare cases, muscular involvement can be the only clinically evident feature of the disease. The clinical pattern of isolated muscular vasculitis may mimic several other inflammatory muscle disorders, such as idiopathic inflammatory myositis, and may represent a challenge in differential diagnosis. Herewith, we present two clinical cases as examples of peculiar clinical and histopathological characteristics of isolated muscular vasculitis. Our patients were successfully treated with steroids and immunosuppressive agents. Moreover, we provide a review of the recent existing medical literature. Our cases suggest the importance of performing muscle biopsy in patients with muscular symptoms to guide the diagnosis and the treatment.

Competing Interests: We have read and understood BMJ policy on declaration of interests and declare that we have no competing interests.

Systemic necrotizing polyarteritis was diagnosed in three 7-11-mo-old lambs from the same flock. Aneurysmal dilation and rupture of the gastroduodenal artery in 1 lamb resulted in fatal hemorrhage. All lambs had severe necrotizing vasculitis involving the small intestine, abomasum, mesentery, kidney, and heart with concurrent lymphocytic enteritis. Immunohistochemistry for T- and B-lymphocytes and macrophages found a T-cell- and macrophage-dominant transmural vascular infiltrate and T-cell-associated enteritis. PCR analysis for pestivirus failed to identify infection in 1 lamb, and more extensive viral microarray techniques applied to the second and third lamb failed to detect viral nucleic acid. The identification of 3 cases within 1 flock raises the possibility of a common etiology; however, no cause was established. A genetic etiology was not considered likely as not all of the lambs were related. The presence of concurrent T-lymphocyte-associated enteritis raises the possibility of an immune-mediated disease process linking the vasculitis and enteric lesions.

Cutaneous polyarteritis nodosa (CPAN) is a rare diagnosis which is distinct from polyarteritis nodosa (PAN). PAN is a medium-vessel vasculitis which can affect multiple organs and classically produces microaneurysms in the vasculature. CPAN is limited to the skin mainly affecting small vessels. There is an absence of microaneurysms in CPAN and it does not affect internal organs. However, the histopathological findings on the skin are similar to PAN. CPAN rarely progresses to PAN but relapses more often. We will illustrate a challenging case of a patient with CPAN who developed gangrenous infarcts despite initial immunosuppressive treatment with high-dose steroids and azathioprine. His treatment had to be escalated to intravenous cyclophosphamide which induced disease remission., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)