A 31-year-old Vietnamese woman in her 28th week of gestation complained of a pruritic, blistering rash that began at approximately the same time as her pregnancy. She had no history of similar problems during her previous pregnancy. Erythematous patches with erosions, crusting, and occasional vesicles were present over her right parietal scalp, right forearm, back, and abdomen, including the umbilicus. She had no mucosal involvement.