Allergic contact dermatitis due to chloramphenicol with prurigo nodularis-like spreading.

Topical drugs containing chloramphenicol and clostridiopeptidase A are frequently used for the treatment of cutaneous ulcers and other necrotic lesions. Chloramphenicol is a bacteriostatic broad-spectrum antibiotic widely used in eye and skin ointments to treat bacterial infections and a well-known cause of allergic contact dermatitis (ACD) (1). Clostridiopeptidase A, also called collagenase 1, is a proteolytic enzyme facilitating the tissue granulation with consequent re-epithelization; it has rarely been reported as cause of ACD (2).