Vasodilatory adverse events associated with topical imiquimod 5 percent cream.

The immune response modulator, imiquimod, has a wide ranging utility in dermatology. Some rare adverse events are easily explained based upon its mechanism of action (such as induction of vitiligo and worsening of psoriasis). We report the occurrence of cutaneous vasodilatory side effects, angioedema and urticaria, which accompanied the treatment of basal cell carcinomas in two patients. These phenomena must be quite rare considering a paucity of similar reports in the literature.