Deep Dermatophytosis Presented as Multiple Exophytic Masses caused by Trichophyton rubrum in Immunocompromised Patient with Rheumatoid Arthritis; A Case Report

Abstract

Dermatophytes invade the stratum corneum and infect the skin, nails, and hair, mostly resulting in superficial infections. Deep dermatophytosis involving the dermis and subcutaneous layer has rarely been reported in immunocompromised individuals. Herein, we report a case of deep dermatophytosis caused by Trichophyton rubrum. A 71-year-old woman presented with multiple erythematous exophytic and subcutaneous nodules in both the lower legs. The patient was taking immunosuppressive agents for rheumatoid arthritis and antifungal agents for tinea pedis and onychomycosis, which was improperly ceased. Histopathological findings showed diffuse granulomatous infiltration with multinucleated cells, lymphocytes, histiocytes, and neutrophils in the dermis. Septate and branched hyphae were observed in the dermis using periodic acid-Schiff diastase and Gomori methenamine silver staining. T. rubrum was identified in fungal culture from the tissue sample and confirmed through phylogenetic analysis of the internal transcribed spacer and large subunit regions in ribosomal ribonucleic acid gene. Intravenous amphotericin B was administered for septic shock before the confirmation of the causative organism, which rapidly improved the condition.