We report a case of invasive dermatophytosis mimicking vasculitis. A patient consulted the Department of Dermatology, Zealand University Hospital, Roskilde, Denmark for the assessment of violaceous/erythematous lesions thought to be vasculitis. She had prior to this been treated with the immunosuppressive drug teriflunomid. Due to the lesion's erythematous scaling boarder invasive dermatophytosis was suspected. By using direct microscopy a mycological diagnosis was confirmed. We underline the utility of direct microscopy in the diagnosis.