Severe sporotrichoid fish tank granuloma following infliximab therapy.

Mycobacterium marinum is an atypical mycobacterium usually found in non-chlorinated water. It rarely disseminates, except in the setting of a severely immunosuppressed patient, and usually follows a sporotrichotic type of distribution. We report the case of a 45-year-old man who had ankylosing spondylitis and was receiving infliximab and isoniazid for latent tuberculosis. The patient presented with a 5-month history of painful erythematous and suppurative nodules and abscesses on the right upper extremity. M. marinum was not isolated in cultures and histologic findings together with clinical examination provided evidence of sporotrichoid-like fish tank granuloma. The patient was treated with rifampin (rifampicin) and ethambutol for 8 months and responded satisfactorily while continuing to receive infliximab. In accordance with data in the published literature, isoniazid proved ineffective in preventing M. marinum infection in this patient. While mycobacterial complications of tumor necrosis factor-alpha (TNFalpha) inhibitor therapy are well established, our case appears to be the first reported instance of M. marinum infection in a patient taking infliximab. As anti-TNFalpha agents become increasingly used for a variety of conditions, awareness of the potential infectious complications associated with use of these agents will be vital for clinicians.

Pimecrolimus induced tinea incognito masquerading as intertriginous psoriasis.

A 58-year-old, obese, male, army officer was presented with tinea incognito of the groin masking intertriginous psoriasis. According to his history, he had pruritic, symmetrical erythematous eruption of the groin of 2-month duration that he treated himself by using topical pimecrolimus 1%. This medication had been prescribed for his 8-year son's atopic dermatitis by the paediatrician. Direct examination with potassium hydroxide preparation showed fungal hyphae and Trichophyton rubrum was isolated in culture. This is the second case of topical pimecrolimus induced tinea incognito. We also review the cutaneous disorders that tinea incognito may mimic.

Treatment of Mycobacterium marinum cutaneous infections.

Mycobacterium marinum is a non-tuberculous mycobacterium found in non-chlorinated water, with worldwide prevalence. It is the most common atypical Mycobacterium that causes opportunistic infection in humans. It presents as a solitary, red-to-violaceous plaque or nodule with an overlying crust or verrucous surface, or as inflammatory nodules or abscesses, usually in a sporotrichotic type of distribution. Deep infections may also occur. Although diagnosis is confirmed by isolation and identification of the organism in practice diagnosis remains largely presumptive based on clinicohistological features and the response to treatment. Polymerase chain reaction allows the routine early detection of the organism from a biopsy specimen. In the near future, it seems possible that histopathological examination might be greatly assisted by the rapidly improving possibilities with in vivo imaging. There have been many therapeutic modalities used effectively in the treatment of M. marinum infections. Spontaneous remission has also been reported in untreated infections and in immunocompetent hosts. However, there is no proven treatment of choice because M. marinum is naturally multi-drug resistant species and treatment is based primarily on the personal experience and preference of individual investigators, without the benefit of large studies. In superficial cutaneous infections minocycline, clarithromycin, doxycycline and trimethoprim-sulfamethoxazole as monotherapy are effective treatment options, but drug resistance varies and thereby combination therapy usually of two drugs may be required. Ciprofloxacin has shown considerable effectiveness. In cases of severe infections, including those with a sporotrichoid distribution pattern, a combination of rifampicin and ethambutol seems to be the recommended regimen. The use of isoniazid, streptomycin and pyrazinamide as empirical treatment options should be avoided. Surgical treatment is not usually recommended and must be cautiously applied. Cryotherapy, X-ray therapy, electrodesiccation, photodynamic therapy and local hyperthermic therapy have been reported as effective therapeutic alternatives. M. marinum infection should always be included in the differential diagnosis of all cases with poor-healing wounds in upper extremities and a history of exposure to aquariums.

Ultrastructural immunocytochemistry of autoimmune bullous diseases.

Advanced immunopathological assays have been developed to elucidate the pathophysiology and provide more precise nosological definitions of the immunobullous diseases. Forty-seven patients suffering from autoimmune bullous diseases (intra- or subepidermal) were studied by immunoelectron microscopy (direct and indirect). Peroxidase staining was revealed by diaminobenzidine (determination of immune deposit location) in the majority of the cases of subepidermal bullous diseases, but in less than half of the cases of intraepidermal bullous diseases. Immunoelectron microscopy features contributed in verifying the diagnosis of rare entities such as cicatricial pemphigoid, paraneoplastic autoimmune bullous disease, linear IgA disease and epidermolysis bullosa acquisita.