Vitamin B-12 induced acnes.

A type of acne induced by vitamin B-12 deserves a special place among acneiform eruptions. The eruption is monomorphic and of a particular type. It consists of voluminous folliculitis lesions which develop acutely after the first injections of vitamin B-12 and disappear rapidly when treatment is discontinued. The etiologic and pathogenic mechanisms of the disease are not know.