The authors report 4 cases of eczematous-1ike drug eruption after oral ingestion of pristinamycin (3 cases) and virginiamycin (1 case). The lesions occurred after contact sensitization with topical virginiamycin. The clinical symptoms appeared a few hours after ingestion: a generalized maculopapular eruption, sometimes with general symptoms of anaphylactic reaction. Eczema appeared again on initial areas of contact dermatitis. There is a common allergenic group between these 2 antibiotics, which is a macrocyclic lactone. Physiopathology of this drug eruption is not clear: allergic reaction of the delayed type or anaphylactic reaction. Patients allergic to virginianmycin should be strongly cautioned against oral pristinamycin.