Linear IgA bullous dermatosis: A rare manifestation of amoxicillin‐clavulanic acid treatment

Dear Editor, A 27-old year woman with type 1 diabetes was admitted to our dermatology department with a 2-week history of nonpruritic vesiculobullous eruption involving skin and mucosa. The eruption occurred 6 days after receiving amoxicillin-clavulanic acid treatment (2 g/d) for an upper respiratory tract infection. Vital parameters were stable on presentation. Clinical observation revealed multiple 0.3 to 1 cm tense blisters, superficial erythematous erosions and targetoid macules with central crusting. The vesicles were grouped in “crown of jewels” pattern (Figure 1). In addition, the patient had some oral and genital mucosal erosions. Lesions were located along the extensor surfaces of her arms and legs, as well as her neck and trunk. She had no gastrointestinal complaints. No change in her long-term medication was made. Laboratory findings were unremarkable and included negative antinuclear antibodies and anti-double-stranded DNA antibodies. Histopathological examination revealed a subepidermal cleavage with intense neutrophilic infiltrate and neutrophil microabscesses within the dermal papillae without keratinocyte necrosis. Direct immunofluorescence of the perilesional skin demonstrated isolated linear immunoglobulin A (IgA) deposits at the basal membrane zone, which was consistent with linear IgA bullous dermatosis (LABD) (Figure 2). On the basis of the history and correlation of events to the initiation of amoxicillin-clavulanic acid, drug-related LABD was suspected. Discontinuation of amoxicillin-clavulanate and initiation of treatment with oral dapsone and topical clobetasol propionate cream led to rapid resolution of the skin lesions within 3 weeks, without recurrence at 6-month follow-up. Naranjo adverse drug reaction algorithm was used to assess imputability of amoxicillin-clavulanate resulting with a “probable” association (a score of 5).