000258 - Childhood linear iga bullous dermatosis likely induced by amoxicillin–clavulanate: a single case report

Background: Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease in children, characterized by subepidermal blister formation and linear IgA deposition along the basement membrane zone. Although LABD is often idiopathic, it may be triggered by medications, most commonly vancomycin and, less frequently, beta-lactam antibiotics.

Case Presentation: A 5-year-old child presented with a 14-day history of severe pruritus and widespread bullous lesions involving the trunk and extremities. The eruption initially appeared as erythematous plaques and subsequently progressed to tense, clear, and hemorrhagic blisters. The lesions demonstrated a characteristic annular “string-of-pearls” configuration, with peripheral vesiculation and central clearing. Medical history revealed recent treatment with amoxicillin–clavulanate for a respiratory tract infection.

Investigations: Physical examination showed extensive bullae and crusted erosions, with mild oral mucosal involvement. Histopathological examination demonstrated subepidermal blistering with a predominantly neutrophilic infiltrate. Direct immunofluorescence (DIF) revealed a continuous linear deposition of IgA along the dermoepidermal junction, confirming the diagnosis.

Diagnosis: Based on the clinical presentation, histopathological findings, and DIF results, a diagnosis of childhood LABD was established, most likely induced by amoxicillin–clavulanate.

Conclusion: This case highlights the classic “necklace of jewels” presentation of childhood LABD and underscores the essential role of direct immunofluorescence in achieving a definitive diagnosis. It also emphasizes that commonly prescribed antibiotics should be considered potential triggers for LABD in pediatric patients