Infantile bullous pemphigoid with "string of pearls sign".

Bullous pemphigoid (BP) is an immune mediated bullous disease that is manifested by urticarial plaques with superimposed subepidermal blisters and significant pruritus. It is generally found in the elderly, but is rare in the pediatric population. A 5-month-old girl previously diagnosed with hand-foot-mouth disease was examined in our dermatology department owing to vesicles and bullae, initially located to the hands and feet, which progressed with new lesions. Tense vesicles and bullae distributed in an annular string of pearls pattern on the abdomen and facial and cervical regions were noted. Histologic and immunologic findings were consistent with the diagnosis of infantile BP. Disease control was obtained with oral prednisolone and dapsone; the patient was still in clinical remission 6 months after treatment cessation. The differential diagnosis of the clinical presentation of the lesions in our patient is of note, given that this blistering pattern is frequently reported in association with linear IgA bullous dermatosis.