A 33-year-old African American woman came to the office with a 2-week history of skin lesions and itching. The lesions started with a single blister on her left elbow; numerous other blisters subsequently appeared on her forearm and hands. One week before this visit, she had been given a presumptive diagnosis of bullous impetigo and was treated with cephalexin.
Despite the antibiotics, other lesions soon appeared in the nuchal and breast folds, axillae, and scalp areas. Several had ruptured, producing purulent, malodorous material. She had no known allergies, no medical problems aside from obesity, and no significant family history or recent travels. She denied any illicit drug use and had not been on any medications.
On physical exam, 1 large bulla was seen on the fourth digit of her left hand (Figure 1). The patient was obese, and inspection of the skin folds of her abdomen showed multiple suppurative lesions and erosions where previous bullae were found (Figure 2). No oral or gingival erosions were seen. Labs showed a white blood cell (WBC) count of 10.5 x109L], hemoglobin of 11.0 g/dL, and hemoglobin A1cof 5.5; liver function tests were normal. Gram stain showed no WBC and had rare Gram-positive bacilli. Potassium hydroxide prep of a skin lesion scraping showed no fungal elements. A herpes culture was performed along with a punch biopsy.
FIGURE 1
Bulla on the index fingerLeft index finger bulla, which appeared 10 days after onset of disease.
FIGURE 2
Multiple bullae on the trunk
What is the diagnosis?