A 9-YEAR-OLD girl was referred to the Pediatric Dermatology and Cutaneous Laser Center, Baltimore, Md, for evaluation of a blistering rash on the thighs and perineum (Figure 1). The eruption was mildly pruritic and resembled herpes simplex virus type 1. However, the results of a previous examination for sexual abuse, including multiple viral cultures, were normal.
The child appeared healthy and afebrile. The results of the examination showed nontender, tense vesicles and bullae, which were confined to the inner thighs, labia, and perineum. No crusts or excoriations were present.
A Gram stain, Tzanck test, and bacterial and viral cultures of the blister fluid were negative for viruses and bacteria. Complete blood cell count with differential cell count was normal. The histologic condition of a skin biopsy specimen demonstrated subepidermal blister formation (Figure 2). Immunofluorescence revealed a linear pattern of IgA deposition along the basement membrane zone (Figure 3).