A 23-year-old G2P1001 with an intrauterine pregnancy at 30 weeks' gestation presented with a chief concern of a “bump down there” that had become increasingly tender over the previous 2 days. She had a normal prenatal course and laboratory studies, one current sexual partner, and no history of sexually transmitted infections. Examination of the external genitalia revealed a 0.5 cm × 0.5 cm nonfluctuating ulcerated lesion on the right labia majora. The lesion was crusted without exudate, and it was exquisitely tender to palpation. Erythema and induration extended approximately 4 cm × 2 cm around the lesion. A wet prep of her vaginal discharge was negative for hyphae, clue cells, and trichomonas. Bacterial and viral cultures of the lesion were obtained. Empiric treatment with the broad-spectrum first-generation cephalosporin cephalexin (Keflex) 500 mg tid for 7 days was started. Incision and drainage of the lesion was not attempted because it was nonfluctuating and herpes simplex virus (HSV) was a differential diagnosis. Bacterial cultures of the lesion confirmed Staphylococcus aureus sensitive to clindamycin and vancomycin, and resistant to methicillin, erythromycin, penicillin, and cefazolin. Viral cultures for HSV were negative. The antibiotic was switched to clindamycin (Cleocin) 300 mg qid for 10 days based on the antibiotic susceptibility laboratory report, and the lesion resolved in approximately 2 weeks.