Epidermolysis bullosa acquisita with ultraviolet radiation sensitivity

A 37-year-old male patient developed a bullous eruption and erythematous plaques mainly in exposed areas following prolonged sun exposure. In addition, blisters were noted on oral and nasal mucous membranes. Histopathological examination of a lesional skin biopsy revealed a subepidermal blister. Linear deposition of IgG and C3 at the epidermal basement membrane zone was revealed by direct immunofluorescence microscropy of a perilesional skin biopsy. Indirect immunofluorescence on 1 mol/L salt- split skin showed binding of autoantibodies to the dermal side of the split. Immunoblot analysis of dermal extracts demonstrated that the patient's serum contained IgG antibodies against type VII collagen, whereas no reaction was seen with epidermal extracts or by enzyme-linked immunosorbent assay using a recombinant form of bullous pemphigoid 180. Standardized ultraviolet (UV) radiation provocation induced blistering with both UVA (13.5 J/cm²) and UVB (0.04 J/cm²) within 24 h clinically and histologically. External and systemic UV-protective medication and nine cycles of high dosage immunoglobulins given intravenously (1.2 g/kg body weight over 2-3 days every 4 weeks) resulted in the cessation of blister formation. To the best of our knowledge, this is the first report of a case of epidermolysis bullosa acquisita with sensitivity to UV.