Tense blisters with IgA deposits

Case history

A 63-year-old woman underwent cardiac surgery and developed a wound infection 10 days later. Culture grew methicillin-resistant Staphylococcus aureus. Vancomycin and ciprofloxacin were commenced. Prior medications included irbesartan and atenolol. Six days after commencing antibiotic therapy, widespread urticarial lesions appeared on the patient’s trunk and limbs. The lesions on the palms and soles rapidly developed into large blisters. There were no mucous membrane lesions. Skin biopsy revealed a subepidermal blister with neutrophils at the blister base. Linear deposits of IgA were found on immunofluorescence of frozen skin sections.