a) fixed drug eruption _ _ _ _ _ _ _ _ _ _ Wrong answer ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ b) Bowen’s disease _ _ _ _ _ _ _ _ _ _ Wrong answer ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ c) Zoon’s balanitis _ _ _ _ _ _ _ _ _ _ Correct ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ d) Behçet’s disease _ _ _ _ _ _ _ _ _ _ Wrong answer ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ e) lichen planus _ _ _ _ _ _ _ _ _ _ Wrong answer ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ Answer and Commentary _ _ _ _ _ _ _ _ _ _ All the conditions listed may occur on the glans of the penis. Zoon’s balanitis, also called plasma cell balanitis, presents with a brightly red, erythematous, circumscribed plaque. The surface is slightly moist and the patient is almost always uncircumcised. The lesions persist indefinitely. The cause is unknown. Bowen’s disease, which on the glans of the penis is also called erythroplasia of Queyrat, has a more velvety appearance but a biopsy is always required to differentiate the two conditions: in Zoon’s balanitis this shows a chronic inflammatory infiltrate rich in plasma cells, while in Bowen’s disease the findings are those of an intraepidermal squamous cell carcinoma. ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯
