We report a 15-year-old primagravida female with a history of chronic plaque psoriasis who developed impetigo herpetiformis at 28 weeks gestation. Culture of a needle aspirate from a tender, enlarged cervical lymph node grew Staphylococcus aureus. The patient improved rapidly on wet dressings, topical midpotency corticosteroids, and intravenous nafcillin. The remainder of her pregnancy was uncomplicated. We speculate that both pregnancy and infection led to this pustular flare of her psoriasis.