A Young Man with Pyomyositis and Bullous Disease

Abstract

Diagnosis: linear IgA bullous dermatosis (LABD). Direct immunofluorescence staining of the skin biopsy specimen obtained from the left thigh, the predominant site of the outbreak of multiple small bullae (figures 1 and 2), revealed the presence of linear IgA deposits along the basement membrane (figure 3) consistent with the diagnosis of LABD related to vancomycin therapy. LABD is an autoimmune subepidermal vesiculobullous disease characterized by IgA deposition in a linear pattern along the basement membrane zone [1]. The disease is mediated by autoantibodies directed against several components of the basement membrane zone [2, 3]. Among antimicrobial drugs, vancomycin is the agent that is most frequently involved in cases of drug-induced LABD. Vancomycin-induced LABD is not dose dependent and has heterogenous presentation, ranging from benign erythema multiforme to toxic epidermal necrolysis [4–6]. The lesions appear 1–15 days after initiation of vancomycin therapy. Spontaneous and complete healing occurs after withdrawal of vancomycin therapy. However, new lesions could still appear up to 2 days after withdrawal of treatment with the drug. The use of steroids and dapsone do not seem to improve the outcome [4]. Rechallenge reproduces the disease with more-rapid and moresevere onset; however, successful rechallenge has been reported [7]. In our patient, vancomycin therapy was switched to daptomycin therapy, and the patient’s bullous rash resolved several days later.