Drug-induced versus drug-triggered pemphigus

112 cases of induced pemphigus were reviewed. The causative drugs were divided into three groups according to their chemical structure, and the clinical, prognostic and laboratory characteristics were analyzed and compared. Our literature screening indicates that the biological progress and clinical course of the disease depend upon the type of the inducing/triggering drug in the majority of patients. Patients with penicillamine-induced pemphigus or with pemphigus induced by SH drugs (drugs containing a sulfhydryl radical) showed spontaneous recovery in 39.4 and 52.6%, respectively, once the drug was discontinued. Patients whose pemphigus was induced by other drugs showed spontaneous recovery in only 15% of the cases. These results indicate that in patients with pemphigus induced by penicillamine (or SH drugs), the drug plays a major role in the pathogenesis of the disease, as compared to patients with pemphigus induced by other drugs. It seems that penicillamine (and SH drugs) actually induces pemphigus in most of the cases, whereas other drugs only trigger the disease in patients with a previous predisposition.