Case Report. Bilateral sporotrichosis

Rare diagnosis of nodular lymphangitis caused by Mycobacterium marinum: MDCT imaging findings

Mycobacterium marinum is an atypical mycobacterium that usually causes a solitary nodule on the hand (“fish tank granuloma”) or less commonly, secondary erythematous channels and nodules spread along lymphatic drainage of the extremity, mimicking sporothricoid skin lesions of nodular lymphangitis. This report presents a case of this rare entity, a nodular lymphangitis caused by Mycobacterium marinum. Multidetector computed tomography (MDCT) imaging was very useful in determining the morphology (cellulitis with a few small subcutaneous nodules and channels) and the extension of the lesion.

[Simultaneous bilateral lymphangitic sporotrichosis]

BACKGROUND

Sporotrichosis is the most frequent subcutaneous mycoses in Jalisco, Mexico. The forms of transmission described in the literature are from bites of different animals and injuries due to utensils.

AIMS

To present an unusual case with bilateral and lymphangitic cutaneous lesions in the upper limbs caused by a pocket gopher bite (Geomys bursarius).

METHODS

Mycology studies were performed on the arm lesions, including Gram and Ziehl Neelsen stains, direct exam, Sabouraud and mycobiotic cultures at temperatures of 25-28 degrees C.

RESULTS

Gram and Ziehl Neelsen stains were negative. Sporothrix schenckii grew in the culture plates. Treatment with saturated potassium iodide solution was prescribed and four months later complete remissions of the lesions were achieved, and the control cultures were negative.

CONCLUSIONS

The most common clinical presentations of sporotrichosis are the fixed and lymphangitic forms. Bilateral lymphangitic sporotrichosis is rare.

[Experimental cutaneous sporotrichosis: in vivo evaluation of itraconazole and terbinafine]

The aim of this study was to evaluate the in vivo activity of itraconazole and terbinafine for treating experimental cutaneous sporotrichosis. Eighty Wistar rats were used, divided into four groups (TERB20, TERB30, ITRA and CONT). They were inoculated in the left plantar pad with 0.2 ml of solution containing 2x10(3) cell/ml of Sporothrix schenckii and treated with terbinafine (20 and 30 mg/kg), itraconazole (10 mg/kg) or placebo for 13 weeks. The lesions at the inoculation site were evaluated and measured weekly, along with their dissemination. Mycological and histopathological analyses were performed subsequently. The results showed that the animals in the ITRA group differed statistically in all parameters evaluated, in relation to CONT. For terbinafine, there were no statistical differences between the treated and control groups. It could be confirmed that itraconazole presented good activity for treating sporotrichosis, while terbinafine was ineffective for this disease at the doses used. However, more studies on the latter antifungal agent are needed.

Disseminated sporotrichosis mimicking sarcoidosis

A 40-year-old Caucasian man presented to the dermatology clinic at Baylor College of Medicine, Houston, Texas, in February 2003, for the evaluation of three nonhealing ulcers. The patient's past medical history was significant for hypothyroidism and pulmonary sarcoidosis, the diagnosis of which was made in June 2000. In March 2000, the patient had complained of cough and shortness of breath. A purified protein derivative (PPD) (Mantoux text) was negative. Computed tomography (CT) scans of the chest revealed diffuse hilar and mediastinal adenopathy and bilateral interstitial and alveolar infiltrates. Although consistent with sarcoidosis, these findings were insufficient to exclude other etiologies, including disseminated fungal infection. Cultures and stains of subsequent bronchoscopy specimens failed to reveal any organisms, and histopathologic evaluation of the specimens was nondiagnostic. Based on the imaging studies and the negative cultures, a diagnosis of sarcoidosis was made, and the patient was started on therapy with prednisone. Before coming to our clinic, the patient had been on several courses of prednisone. In May 2002, the patient had presented to a private dermatologist with a 1-year history of a nonhealing 2.4 cm x 2.0 cm ulcer on the left medial forearm. Two biopsies were reported as nondiagnostic. The patient's presentation was interpreted as most consistent with Mycobacterium marinum infection, and so he was empirically treated with minocycline. This treatment was continued for almost 3 months without improvement in the ulcer. A few months after the minocycline had been discontinued, the patient was treated empirically for 2 months with ciprofloxacin. This treatment was also unsuccessful in ameliorating the ulcer. In between the two courses of antibiotics, specimens from the lesion were sent for bacterial and fungal cultures, which revealed normal skin flora. In January 2003, the patient returned to his private dermatologist with three ulcerations. In addition to the nonhealing ulcer on his left forearm, which he had acquired several months earlier, he had also developed a 3.0 cm ulcer on his right arm and a 3.0 cm ulcer on his central back. The patient refused biopsies at this visit. Given the patient's previous diagnosis of pulmonary sarcoidosis, it was thought that the skin lesions might represent ulcerative cutaneous sarcoidosis. Pyoderma gangrenosum was also considered to be a likely diagnosis. Therefore, the patient was started on a course of oral prednisone, an effective therapy for both sarcoidosis and pyoderma gangrenosum. Despite 1 month of treatment with 60 mg/day of prednisone, the ulcers increased, and the patient was subsequently referred to our clinic. Physical examination at the time of presentation revealed steroid acne on the trunk and upper extremities and three non-tender ulcers with erythematous, undermined borders (Figs 1-3). On the left arm, there was an adjacent nodule which the patient attributed to a scar from a previously healed ulcer. Histologic examination of biopsy specimens from all three sites showed similar findings. The lesion contained diffuse, suppurative, granulomatous, inflammatory infiltrates with extensive central necrosis. The infiltrates were composed of histiocytes, multinucleated foreign-body-type giant cells, plasma cells, lymphocytes, neutrophils, and neutrophil fragments. No organisms were seen in the initial, routinely stained sections. However, periodic acid-Schiff (PAS) staining demonstrated small fungal spores (Fig. 4) morphologically consistent with sporotrichosis, within the cytoplasm of multinucleated histiocytic giant cells (Fig. 5). Additional stains for bacteria and acid-fast organisms were negative. Cultures of the biopsy specimens from all three sites grew Sporothrix schenckii. Further questioning of the patient failed to reveal an obvious source of the infection. The patient denied any history of traumatic skin inoculation and did not engage in gardening or other outdoor activities that are classically associated with sporotrichosis. The patient did admit to blackberry picking on detailed retrospective questioning. Once the diagnosis of sporotrichosis was made, the patient was given 200 mg/day of itraconazole. After 2 months, the patient's ulcers were almost completely healed. The patient's pulmonary complaints were also much improved.

Subcutaneous bilateral sporotrichosis : A rare presentation

Sporotrichosis is the most common subcutaneous mycosis observed in Brazil as well as in different regions of the world. We report a rare case of sporotrichosis in a Caucasian male agricultural worker whose lesions occurred bilaterally and simultaneously on the upper limbs.