Lesional biopsy showed a subepidermal bulla with an underlying neutrophilic infiltrate. No epidermal necrosis was present (Figure 2). Subsequent direct immunofluorescence of perilesional skin revealed linear deposition of IgA, IgG, and C3 at the dermoepidermal junction (anti-IgA antibody shown in Figure 3). The results of indirect immunofluorescence were negative. The patient's lesions showed signs of improvement within 2 days of the discontinuation of vancomycin therapy and the initiation of methylprednisolone therapy. The erythroderma resolved within 6 days. Complete resolution of all skin lesions occurred within 3 weeks.