The use of occlusive plastic films has increased the effectiveness of topical corticosteroid therapy, but certain precautions are necessary with this technique. A serious complication—furunculosis—is illustrated by the 2 case reports of this paper. In addition to guarding against skin infections, care should be taken that the plastic films are not readily flammable and that thermal homeostasis is not seriously impaired. Because of the severity of infections acquired in the hospital, it is suggested that the use of occlusive plastic films for corticosteroid therapy in hospitalized patients be restricted. Corticosteroids under conventional wet dressings provide a good substitute method of therapy.