A 2.5-month-old male infant (born by cesarean section, weighing 3650 g) received one dose of DPT vaccine (against diphtheria, whooping cough, and tetanus), one dose of SABIN vaccine, and one dose of Vaxgrip, a vaccine of purified inactivated myxovirus influenza on September 6, 1996. Five days later, he developed symmetric, pruritic, vesiculobullous lesions which began on the trunk and, over five days, progressively spread to the upper and lower extremities, hands, feet, and face. The clinical appearance is illustrated in Fig. 1. Laboratory studies performed at the time revealed a white blood cell (WBC) count of 8800, with 6% eosinophils, and negative serologic tests for syphilis and urine culture. Seventeen days following the onset of the eruption, tense blisters of varying size on erythematous bases, and occasionally in a rosette distribution at the periphery of urticarial plaques, appeared on the hands and feet and then spread to the torso and extremities. There was no mucosal involvement or systemic manifestations. The blister fluid was yellowish and cultured positive for Staphylococcus aureus. The WBC count was 34,600/mm3 with 35% eosinophils. Serum levels of immunoglobulin G (IgG) were 52 mg% (normal, 678-1714 mg%), IgA = 62.1 mg% (normal, 73-422 mg%), IgM = 81.1 mg% (normal, 54-296 mg%), and IgE = 248.7 U/ml (normal, 4.1 U/ml). Three days later, the WBC count had further increased to 55,400 with 48% eosinophils. The biopsy of a trunk lesion showed a subepidermal blister containing large numbers of leukocytes and eosinophils. The cleavage was just below the basal layer. There was a variable degree of hydropic degeneration of the basal cells. In the epidermis, there was slight spongiosis in the spinous layer and exocytosis of leukocytes, neutrophils, and eosinophils. On the epidermal side of the blister, the interpapillary crests were generally reduced, as were dermal papillae on the floor of the blister. The capillaries in the papillary dermis were dilated and congested, and surrounded by a large number of leukocytes and eosinophils. Eosinophils were also present among collagen fibers, which were dissociated by edema. There were also some leukocytes and neutrophils in the dermis. Indirect immunofluorescence (IIF) was positive for circulating basement membrane zone (BMZ) antibodies at a titer of 40. Against salt-split normal human skin, the BMZ antibodies reacted to the epidermal side of the split in a pattern typical of bullous pemphigoid (BP) (Fig. 2). Direct immunofluorescence (DIF) studies were positive for linear deposits of C3 at the BMZ. There were no abnormal deposits of IgG, IgM, or IgA. By immunoblotting, the BMZ antibodies reacted to antigens of 230 kD and 180 kD that comigrated with authentic BP antigens. No antibodies to these antigens were detected in the mother's blood or milk by immunoblotting (Fig. 3). The patient was started on treatment on September 20, 1996 with prednisone, 2 mg/kg/day, dapsone, 2 mg/kg/day, erythromycin, 26 mg/kg/day, and nicotinamide, 5 mg/day. Cefixime, 8 mg/kg/day, was given for 8 days for treatment of the staphylococcal infection. The doses of prednisone and nicotinamide were gradually decreased as the patient improved. The erythromycin was discontinued after 1 month, and all other medications after 4 months. On October 18, approximately 1 month after the onset of the disease, the patient was no longer forming new lesions. The WBC count had decreased to 23,500 and the eosinophils to 12%. Five days later, there was continued improvement in the clinical picture, although some arciform lesions and blisters were still present. The WBC count had decreased further to 12,900/mm3, the eosinophils to 10%, and plaques to 661.00/mm3. On January 7, 1997, the child was in total clinical remission without any lesions and off all therapy. The WBC count was normal at 7300/mm3, as were the eosinophils at 3% and plaques at 319.00/mm3.
