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Two horses were examined for large head wounds suspected to be the result of trauma and characterized by extensive necrosis of the skin and subcutaneous tissue, with abundant purulent exudate. Corynebacterium pseudotuberculosis was isolated from the facial wounds in both horses. Histopathologic examination revealed severe suppurative cellulitis and panniculitis with fistulous tracts and granulation tissue in 1 horse. Both horses were treated with local wound care, nonsteroidal anti-inflammatory drugs, and administration of antimicrobials. The concept of moist wound care was used in the second horse, with products that have recently become available for veterinary wound management. Outcome in both horses was good.

Inflammation of subcutaneous tissue (panniculitis) may occur in association with tuberculosis, but so far only three cases of non-tuberculous mycobacteria-related lobular panniculitis have been reported. We describe two new cases with marked cellular immunity failure due to hypercorticism. Clinical presentation did not differ significantly from lobular panniculitis of other aetiologies. Histological samples displayed signs of lobular panniculitis and clues for mycobacteria infection with granulomatous lesions and presence of numerous acid-fast bacilli on special staining. Both patients responded quickly to a combination of macrolides, ethambutol and fluoroquinolones. However, like in other infections with tuberculous or non-tuberculous mycobacteria, long-term treatment (at least 6 months) was necessary to prevent relapses.

We describe a 58-year-old man presenting with necrotizing panniculitis of the lower right leg and a 64-year-old woman with a clinically similar lesion combined with pustular eruptions and subsequent ulceration on the forehead. In the first patient, Giemsa staining showed small ovoid bodies and Grocott staining revealed hyphae. Histology from the process on the forehead showed branched filaments in the periodic acid-Schiff (PAS) staining. In the first case, Madurella mycetomatis, a fungus, was the pathogenic agent, whereas in the other case white colonies of filamentous organisms resembling fungi could be cultivated that turned out to be the bacterium Nocardia brasiliensis. Since the initial clinical appearance of these two forms of mycetoma were almost identical and histopathologic findings were inconclusive, only sophisticated microbiologic work-up of material from lesional skin led to the correct diagnosis. In times of global tourism, these unusual cases impressively document the necessity to become more familiar with mycetoma to make accurate therapeutic decisions with effective results, possibly saving a limb.

A 40-year-old woman undergoing prednisolone and cyclosporine therapy for subcutaneous panniculitic T-cell lymphoma complained of a cough for a few weeks. A chest X-ray revealed bilateral diffuse granular shadows. Additionally, the patient was discovered to have multiple subcutaneous abscesses. Gram-stained smears of sputum and pus from the abscess showing branched gram-positive rods led to a diagnosis of pulmonary nocardiosis with dissemination to the lungs and subcutaneous tissues. Combination therapy consisting of sulfamethoxazole/trimethoprim and panipenem/betamipron produced rapid improvement of radiographic abnormalities. It is suggested that pulmonary nocardiosis should be considered in the differential diagnosis of diffuse granular shadows on chest X-rays, especially in immunocompromised patients.

A 16-year-old female white whale, Delphinapterus leucas, died after nearly 18 months of chronic lymphopenia and pyogranulomatous dermatitis. Necropsy revealed rupture of the aorta with hemorrhage into the cranial mediastinum and between fascial planes of the ventral neck musculature. Multiple foci of ulcerative dermatitis and panniculitis were present across the thorax and abdomen and surrounded the genital folds. In addition, there was a chronic proliferative pleuritis with over 20 liters of histiocytic exudate in the thoracic cavity. Acid-fast bacteria consistent with Mycobacterium sp. were identified in sections of skin lesions and in cytospins of pleural exudate. Cultures of pleura and 1 skin lesion collected at necropsy yielded sparse growth of an acid-fast bacillus with colony characteristics and morphology consistent with Mycobacterium marinum. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis confirmed the presence of M. marinum DNA in samples of skin. This is the first documented occurrence of mycobacteriosis in a white whale and is a unique presentation of mycobacterial dermatitis and panniculitis with chronic pleuritis in a cetacean. The improved PCR-RFLP protocol utilized in this case unifies techniques from several protocols to differentiate between species of Nocardia and rapidly growing mycobacteria clinically relevant to aquatic animals.

An eight-year-old neutered female Persian cat with a four-year history of relapsing skin disease, characterised by ulcerated nodules with a yellow granular discharge, was examined. A diagnosis of granulomatous dermatitis and panniculitis (pseudomycetoma) caused by Microsporum canis was made on the basis of history, clinical signs, histopathological examination of skin biopsy specimens and culture of macerated tissue. Because previous therapy, comprising repeated surgical excision and the administration of griseofulvin and itraconazole, had not been successful, terbinafine was administered for an eight-month period. However, lesions progressed despite this treatment and the cat was euthanased.

Mycobacteria were isolated and characterised from 49 cats with extensive infections of the subcutis and skin. Cats were generally between 3 and 10 years of age, and female cats were markedly over-represented. All isolates were rapid-growers and identified as either Mycobacteria smegmatis (40 strains) or M fortuitum (nine strains). On the basis of Etest for minimum inhibitory concentration and/or disc diffusion susceptibility testing, all strains of M smegmatis were susceptible to trimethoprim while all strains of M fortuitum were resistant. M smegmatis strains were typically susceptible to doxycycline, gentamicin and fluoroquinolones but not clarithromycin. All M fortuitum strains were susceptible to fluoroquinolones, and often also susceptible to gentamicin, doxycycline and clarithromycin. Generally, M smegmatis strains were more susceptible to antimicrobial agents than M fortuitum strains. Treatment of mycobacterial panniculitis involves long courses of antimicrobial agents, typically of 3-6 months, chosen on the basis of in vitro susceptibility testing and often combined with extensive surgical debridement and wound reconstruction. These therapies will result in effective cure of the disease. One or a combination of doxycycline, ciprofloxacin/enrofloxacin or clarithromycin are the drugs of choice for long-term oral therapy., (Copyright 2000 European Society of Feline Medicine.)

To evaluate the histopathological features observed in patients with cutaneous infections due to nontuberculous mycobacteria (NTM) and to compare the histopathological patterns observed in immunosuppressed patients and normal hosts. Twenty-eight biopsy specimens corresponding to 27 patients with cutaneous infections due to NTM were reviewed. Eighteen biopsies corresponded to normal hosts (14 Mycobacterium marinum, 2 Mycobacterium chelonae, 1 Mycobacterium terrae and 1 Mycobacterium gordonae) and 10 biopsy specimens were obtained from 9 immunosuppressed patients (3 Mycobacterium chelonae, one of which had two biopsies, 1 Mycobacterium abscessus, 2 Mycobacterium kansasii, 1 Mycobacterium marinum, 1 Mycobacterium avium complex and 1 Mycobacterium simiae). A panel of histopathological features was evaluated by two independent observers in each biopsy specimen. Epidermal changes (acanthosis, pseudoepitheliomatous hyperplasia, exocytosis) were mainly observed in M. marinum infections. In immunosuppressed patients the infiltrate tended to be deeper, involving the subcutaneous tissue (100%) with a more diffuse distribution and constant abscess formation. A marked granulomatous inflammatory reaction was observed in 83% of immunocompetent and in 60% of immunosuppressed patients. In immunosuppressed patients a relationship between the chronic evolution of the disease and granuloma formation was demonstrated. A diffuse infiltrate of histiocytes with occasionally foamy appearance was noted in three biopsy specimens from three patients with AIDS. Acute and chronic panniculitis was detected in 8 biopsy specimens. In one biopsy (M. chelonae) an acute suppurative folliculitis was observed. Different histopathological patterns can be noted in biopsy specimens from cutaneous nontuberculous mycobacterial infections. The evolution of the disease and the immunologic status of the host may explain this spectrum of morphological changes. Tuberculoid, palisading and sarcoid-like granulomas, a diffuse infiltrate of histiocytic foamy cells, acute and chronic panniculitis, non-specific chronic inflammation, cutaneous abscesses, suppurative granulomas and necrotizing folliculitis can be detected. Suppurative granulomas are the most characteristic feature in skin biopsy specimens from cutaneous NTM infections. Some histopathological patterns seem more prevalent in immunosuppressed patients.

Nine pigs with acute erysipelas in skin manifestation have been subjected in 1998 to a bacteriological examination. Eight animals proved to have Erysipelothrix rhusiopathiae in muscles and/or organs. In the part of the well-defined rhomboid, bluish-red skin lesions, histology showed a disseminated acute vasculitis and a perivascular suppurating dermatitis and panniculitis. The actually valid Swiss Meat Inspection Ordinance which in case of erysipelas in skin manifestation requires only the elimination of the skin and admits the consumption of the meat, is not warrantable from the point of view of meat hygiene.

A previously healthy 13-month-old boy developed group A beta-hemolytic streptococcus bacteremia coinciding with numerous eruptive subcutaneous lesions primarily on his extremities. Skin biopsy revealed infectious panniculitis; gram-positive cocci were present within both fat lobules and septa. Molecular genetic analysis of an isolate from the patient's blood revealed an emm type 4 organism displaying the emm chromosomal pattern E that is characteristic of opacity factor-producing strains; the organism also harbored the gene encoding for streptococcal pyrogenic exotoxin C (speC). To our knowledge, this clinical presentation has not yet been described in the spectrum of infections directly caused by group A beta-hemolytic streptococci.

We describe an 82-year-old woman with an acute panniculitis in the left groin as the first sign of chronic renal brucellosis. She was afebrile and had a large erythematoviolaceous plaque with ulceration and liquefaction of the subcutaneous tissue. Histopathologic study showed a septal and lobular panniculitis with neutrophil infiltration, hemorrhage, and necrosis. Microbiologic cultures of a skin biopsy specimen, blood, and urine were negative. A computed tomography scan showed a left "mastic" kidney with a psoas abscess extending to the left inguinal region. The microbiologic culture of the removed renal mass and the serologic tests established the diagnosis of chronic renal brucellosis. Although the clinical picture of cold abscesses in the inguinal area classically suggests a tuberculosis, brucellosis should be included in the differential diagnosis.

Attempts were made to reproduce bovine lechiguana, a disease associated with Dermatobia hominis and Pasteurella granulomatis infections. Suspensions of Pasteurella granulomatis were mixed with each of the following: saponin, oil adjuvant, ground Dermatobia hominis, or 5% mucin. Each preparation was inoculated into 6 cattle. Twelve more cattle, 6 of which received dexamethasone, were inoculated with bacterial suspension alone. Abscesses but no lechiguana was produced in all 36 cattle. After abscess regression, 12 cattle were reinoculated with a suspension of mouse-passed P. granulomatis. Only abscesses were produced. The intralymphatic inoculation of P. granulomatis in 6 cattle did not produce the disease. Eleven cattle infected naturally with D. hominis had lesions containing dead larvae. These lesions were inoculated with P. granulomatis. Nine cattle were experimentally infected with larvae of D. hominis that had been contaminated with the bacteria. No lechiguana lesions were produced in these 20 cattle. Six cattle with severe natural D. hominis infection were inoculated in the larval lesions with P. granulomatis. One developed lesions indistinguishable from those of natural lechiguana. The lesions regressed after treatment with chloramphenicol. D. hominis larvae and exudate from lesions caused by the fly were collected from 7 cattle on 3 farms and examined bacteriologically. P. granulomatis was isolated from the larvae and the exudate of a healthy calf from a farm where lechiguana had never been observed. These results suggest that P. granulomatis has a causal role in lechiguana, and that D. hominis may be a carrier of the bacterium. These observations suggest that lechiguana occurs when severe D. hominis lesions are infected with P. granulomatis. The apparent long incubation period, the negative results obtained in the other experiments, and also the infrequent occurrence of the natural disease suggest that lechiguana is a disease for which Koch's postulates are not easily fulfilled.

A 61-year-old woman had rapidly enlarging ulcers on both legs and three draining subcutaneous nodules on the left thigh. Findings of skin biopsy specimens revealed granulomatous panniculitis with a large number of blastospores and pseudohyphae. Candida albicans was cultured from the ulcers, the nodules, the mouth, the esophagus and gastric juice, feces, and urine. The ulcers healed after 5 months of therapy with itraconazole. Predisposing factors were diabetes mellitus, dysfunction of the hypothalamic-pituitary system, hypochromic anemia, and prior treatment with a broad-spectrum antibiotic. In contrast to three other reported cases of Candida panniculitis, our patient had not undergone immunosuppressive therapy.

In southern Brazil, cattle are affected by a disease known locally as Lechiguana and characterized by large subcutaneous swellings. Eighteen cases were examined clinically; 17 of the cattle had a single swelling, and one had two swellings. In 14 of the 18 cases, the swellings were located over the scapula and adjacent regions. The subcutaneous masses reached maximum dimensions of 45 x 50 cm, with heights above the skin surface of 5-25 cm. Growth was rapid, often taking place in 15 to 60 days. Histologically, all lesions were focal proliferative fibrogranulomatous panniculitis and consisted of focal proliferation of fibrous tissue that was infiltrated by plasma cells, eosinophils, lymphocytes, and sometimes neutrophils. An eosinophilic lymphangitis was also present, which sometimes resulted in the destruction of the lymphatics and the formation of eosinophilic microabscesses. Small granulomas, sometimes containing radiating clubs, and Splendore-Hoeppli material were present in the regional lymph node. Pasteurella granulomatis was isolated from the subcutaneous masses of 14 of the 18 natural cases. All 11 of these cases recovered following treatment with 3 g of chloramphenicol daily for 5 days. Untreated animals died. Because the area of anatomic distribution is similar to that infested by Dermatobia hominis, we postulate that this insect may transmit the causative agent. In one steer, a subcutaneous injection of P. granulomatis caused a large subcutaneous swelling consisting of interlacing bundles of collagen infiltrated by neutrophils, eosinophils, and some lymphocytes. Microabscesses, but not lymphangitis and granulomas, were detected. In all 11 cattle inoculated either intramuscularly or subcutaneously with P. granulomatis, purulent abscesses were produced at the sites of the injection, and P. granulomatis was recovered from all lesions.

We evaluated the histopathologic findings in 15 cases of panniculitis due to infection. Organisms were identified by special staining in 14 cases, and in 6 of these the etiologic agent was confirmed by culture studies. In one additional case, lesional culture was positive despite negative special staining. Eight cases were caused by gram positive or gram negative bacteria, 2 by atypical mycobacteria, 2 by Nocardia, and 3 by fungi (Candida and Fusarium species). Most patients had conditions or were receiving therapies predisposing to immunosuppression, but at least 2 individuals had no other major medical problems. There were some variability in microscopic findings and overlap with established forms of panniculitis; 3 cases (2 due to bacteria and 1 to Fusarium) resembled acute, "neutrophilic" erythema nodosum, and evidence of vasculitis was seen in septicemias due to Pseudomonas, Nocardia, and Fusarium. Nevertheless, several distinctive features associated with infectious panniculitis of diverse etiologies included: epidermal alterations such as acanthosis and parakeratosis; dermal edema with a diffuse or perivascular neutrophilic infiltrate; and mixed septal-lobular panniculitis with neutrophilic infiltration, vascular proliferation and hemorrhage, and necrosis. Infection should be suspected in virtually any case of panniculitis, particularly when occurring in an immunosuppressed patients, but the microscopic features enumerated above should arouse particular suspicion of an infectious process.