Adult cutaneous diphtheria by non-toxicogenic strain: Case report and review of literature

We report an unusual case of recurrently infected post-folliculitis keloid. The diagnosis of cutaneous diphtheria was made by isolation of Corynebacterium diphtheriae cultured from pus collected from the skin lesion. The strain was non-toxigenic on multiplex real-time PCR assay. A prior pus sample from the lesion had grown Methicillin resistant Staphylococcus aureus (MRSA). The patient was treated with oral erythromycin for 14-days. Chemoprophylaxis was advised to the close contacts. The present case emphasizes the importance of investigation for unusual etiologies in patients with non-responding ulcerative cutaneous lesions. Early diagnosis of cutaneous diphtheria is required for appropriate treatment and effective control measures.