Sporotrichosis

Sporotrichosis is an endemic mycosis with worldwide distribution caused by the dimorphic Sporothrix schenckii fungal complex.

The vast majority of sporotrichosis infections are lymphocutaneous or fixed cutaneous forms, although osteoarticular, pulmonary, meningeal, and disseminated sporotrichosis may occur, especially in patients with diabetes, alcohol use disorder, HIV, and hematologic malignancies, but also in normal hosts.

Lymphocutaneous sporotrichosis is caused by traumatic inoculation of the fungus into the skin and results in an initial nodular lesion that usually ulcerates, which is followed by ascending nodular lymphangitis.

The definitive test for diagnosis of lymphocutaneous sporotrichosis is culture of the fungus from skin lesions.

Because of their nonspecific presentation and relative rarity, a high index of clinical suspicion is required for diagnosis of extracutaneous forms of sporotrichosis, which is typically delayed.

Lymphocutaneous sporotrichosis is not life threatening and responds well to itraconazole treatment.

Extracutaneous manifestations of sporotrichosis can be life threatening, especially in immunosuppressed patients, and do not always favorably respond to antifungal therapy.

Sporotrichosis is most often localized in the skin and subcutaneous tissues, following traumatic inoculation of the causative fungus Sporothrix to the dermis of individuals with outdoor vocations and occupations. The majority of sporotrichosis cases are caused by the Sporothrix schenckii complex, which encompasses a group of dimorphic fungi including S schenckii sensu stricto and several cryptic species, such as S pallida, S globosa, S mexicana and S brasiliensis, which are identified in the routine laboratory as S schenckii.