Atypical presentation of herpes simplex virus in a patient with chronic lymphocytic leukemia.

Perianal infections caused by herpes simplex virus are common in immunocompromised patients. The cutaneous presentation in these patients is often atypical, overlaps with the clinical features of other diseases, poses a difficulty in diagnosis, and responds poorly to treatment. An immunocompromised patient with chronic lymphocytic leukemia, treated with oral corticosteroids, presented with chronic perianal ulcerations. This patient was referred for evaluation and treatment of "recalcitrant" pyoderma gangrenosum. Prompt diagnosis was possible when the clinical features were recognized and appropriate biopsy and cultures were obtained. We describe an atypical presentation of herpes simplex virus associated with both an endogenous and exogenous induced immunodeficiency, and stress the importance of routinely performing cultures on all perianal ulcerations and anal fissures to avoid the misdiagnosis, inappropriate treatment, and prolonged discomfort of these afflicted patients.