Abstract

A 76-year-old woman with COPD and rheumatoid arthritis treated with corticosteroids and methotrexate presented from a skilled nursing facility with a 6-month history of necrotic plaques with surrounding erythema of the right upper extremity, left breast, and left lower extremity. The lesions on the left breast and left lower extremity required vacuum-assisted closure and were being followed by a wound care clinic. Biopsy of the right upper extremity was performed due to an inability to heal despite numerous courses of antibiotics. Histopathologic examination revealed small yeast forms in the dermis, approximately 2-4 microns, with occasionally identified budding. There was ulceration with dermal and subcutaneous inflammation of lymphocytes, histiocytes, and neutrophils. The morphology and PAS stain were supportive of a diagnosis of cutaneous histoplasmosis, which was confirmed by MALDI-TOF as histoplasmosis capsulatum. H. capsulatum, a dimorphic fungus, is endemic to the Mississippi River Valley, and most commonly presents as subclinical pulmonary disease.  The incidence of disseminated disease from the lungs to other organs is on the rise due to immunosuppressive medications in posttransplant patients and patients with HIV. Cutaneous manifestations are rare, having only been reported in 10-25% of disseminated histoplasmosis cases. The reported incidence of cutaneous histoplasmosis in patients with an autoimmune condition treated with immunosuppressive medications is limited to a few case reports. This unusual case of histoplasmosis in a patient with rheumatoid arthritis using methotrexate in combination with corticosteroids emphasizes the need for surveillance of this rare complication.