Balanitis Circumscripta Plasmacellularis in a Young Circumcised Male: A Case Report.

A 22-year-old incarcerated Saudi man presented with a 2-day history of painful vesicles on the shaft of his circumcised penis that were unrelated to drug use, trauma, exposure to ill persons, or sexual intercourse. Initial laboratory tests were normal, and the patient was initially diagnosed with herpes simplex infection. Due to nonadherence to the initial antiviral treatment, the lesions progressed, leading to a revised diagnosis of chancroid. Subsequent testing ruled out sexually transmitted infections and revealed methicillin-resistant Staphylococcus aureus in the culture of the purulent exudate. Histopathology confirmed balanitis circumscripta plasmacellularis (BCP, zoon's balanitis). The lesion responded well to topical betamethasone, with marked clinical improvement over 2 months. This case highlights that although rare, BCP should be considered in circumcised patients with non-venereal genital lesions. Additionally, it underscores that early histopathological confirmation is essential to avoid misdiagnosis and inappropriate treatment.