A 15-MONTH-OLD African American boy with a history of atopic dermatitis since the age of 2 months was brought to the emergency department by his mother for an exacerbation of his chronic dermatitis. He had been regularly observed by his primary care physician and dermatologist, and the dermatitis was managed with topical corticosteroids and emollients. Over the 5 days prior to admission, he developed worsening pruritus, increased weeping lesions, irritability, and fever. He had no history of chickenpox; however, he had received a live, attenuated varicella vaccine (Varivax; Merck & Co, Inc, West Point, Pa) 5 days before admission. He had had contact with a visitor with "cold sores" 2 months earlier. On physical examination the child was irritable, uncomfortable, and constantly scratching. Rectal temperature was 40°C. Punched out erosions with an erythematous base were confluent on the face and more discrete on the trunk and upper extremities. Hemorrhagic and golden-colored crusting were evident and numerous excoriations were seen (Figure 1). Two erosions were noted on the soft palate mucosa, and the conjunctivae were normal. Shotty cervical, axillary, and inguinal lymphadenopathy was noted. A specimen for Tzanck testing was prepared by scraping the base of 1 of the facial erosions and staining the cellular material with Wright stain. Numerous multinucleated giant cells were noted on microscopic examination (Figure 2). Viral and bacterial skin cultures and bacterial blood cultures were obtained.