A 32-year-old woman, a cashier (gravida 2, para 1), presented at 19 weeks gestation, complaining of the sudden appearance of itchy red bumps around the belly button. She received an antihistamine (diphenhydramine) and a topical steroid. A few weeks later, she returned with a rash that was getting worse and had spread to her entire abdomen, all extremities, and buttocks, but not her face. Her physical examination shows pruritus and erythematous plaques, with erythema being multiform, but no mucosal membrane is involved. Her past obstetric and medical history were unremarkable. She also denies experiencing similar symptoms. A skin biopsy shows linear C3 staining along the dermo-epidermal junction. Based on the history and physical examination,