Cutaneous Blastomycosis – a case report

Abstract

We present a 46-year-old non-atopic HIV-negative woman from Doboj, Republic of Srpska, Bosnia and Herzegovina, who was referred to the Department of Dermatovenereology, Clinical Center Banja Luka, Republic of Srpska, Bosnia and Herzegovina, with a 3-month long history of an erythematous, large indurated infl amed area on the upper arm. The condition was asymptomatic, immediately following surgical excision of a small tumor. After exlusion of pulmonary blastomycosis and other organ involvement, the diagnosis of primary inoculation cutaneous blastomycosis was made based on clinical presentation and histopathological fi ndings. Histopathology revealed thick-walled, rounded, budding yeasts with broad-based buds that stained pink with periodic acid-schiff (PAS) staining. Itraconazole therapy was initiated at a dose of 2x100 mg/day. After three months of therapy, the dose of itraconazole was increased to 2x200 mg/day during the next three months, and then the dose was reduced to 2x100 mg. Blastomycosis is an uncommon, chronic granulomatous and suppurative mycosis caused by Blastomyces dermatitidis, which belongs to the group of main endemic systemic mycoses and in the great majority of cases represents a primary pulmonary disease. Few sporadic cases have been reported in Europe. There are three forms of blastomycosis: primary cutaneous, pulmonary and disseminated. B. dermatitidis has rarely been isolated from the environment. Wood debris or land close to rivers or subject to fl ooding are considered to be the natural substrate. The fungus can grow in sterile soil in the laboratory, and it is believed that humans get infected by inhaling spores from a saprophytic source. Primary cutaneous blastomycosis is very rare and it is found in farmers and laboratory workers. Human to human transmission does not normally occur. The diagnosis of the skin lesions is made by direct microscopy of skin samples (e.g., pus, scrapings) with 10% potassium hydroxide mount and confi rmed by culture or biopsy. Histopathological analysis provides identifi cation of all the dimorphic fungi. However, this can be complicated by the fact that in some cases they can be morphologically atypical or sterile. In the tissues, B. dermatitidis produces characteristic thick-walled, rounded, refractile, and spherical budding yeasts with broad-based buds. Of the available antimycotic drugs, itraconazole 200 mg/day is probably the most effective, but at least 400 mg/day is redommended initially.