PA04 (P05) A rare presentation of blistering in an adolescent

Abstract

A previously well 16-year-old male presented with florid and widespread tense bullae and erosions. He gave a 2-week history of an erythematous rash consisting of crusted erosions that started on his chest and face. He denied any new medications or over-the-counter preparations. There was no preceding systemic illness, and no history of cold sores or sexual contacts. In the 24 h prior to his admission, his rash had become widespread, involving his trunk, limbs, hands, ears, face, lips, oral and genital mucosa. He had started to feel systemically unwell and was in significant pain. On examination, he had a combination of heavily crusted erosions and extensive tense bullae containing straw-coloured fluid on a background of inflamed skin. The morphology was herpetiform in some areas. There was notable extension of bullae onto the palms and penis, as well as intraoral and labial erosions. Viral skin swabs were negative, and his biopsy subsequently demonstrated subepidermal blistering with neutrophil-rich inflammation and positive direct immunofluorescence (IMF) for C3 and IgG only. Serum autoantibodies were negative. Childhood bullous pemphigoid (BP) was initially the working diagnosis, but indirect IMF showed localization to the base of the blister and anticollagen VII antibodies later proved positive, consistent with a diagnosis of epidermolysis bullosa acquisita (EBA). Given the clinical features, it was classified as BP-like EBA. He was initially treated with high-dose oral prednisolone, superpotent topical steroids and analgesia as an inpatient. Mycophenolate mofetil (MMF) was initiated, and his corticosteroid dose was slowly tapered. His condition was completely controlled with MMF 500 mg twice daily at 4 months. The patient then elected to stop taking MMF and remains in complete remission at 7 months. The EBA is rare in adults and even more so in children. The mean age of onset is 44–54 years, but up to 5% of reported cases are in children/adolescents. Four subtypes are described: classic mechanobullous, BP-like, mucous membrane pemphigoid-like and linear IgA bullous dermatosis-like. The BP-like EBA is characterized by widespread vesicles and tense bullae, commonly on an inflammatory background and lacking skin fragility, scarring or milia. Oral and genital mucosae are frequently affected in paediatric cases of EBA. Various steroid-sparing treatment modalities are described, including dapsone, colchicine and MMF. The prognosis in the paediatric population is favourable compared with that of adults: the majority achieve complete remission or complete control on treatment.