Visual Diagnosis: A 7-Month-Old Who Has a Persistent Rash

Abstract

1. Angel Alberto Herrera Guerra, MD* 2. Russell J. Osguthorpe, MD† 3. Angelica Putnam, MD§ 4. Sheryll L. Vanderhooft, MD‡ 1. *Fellow, Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, UT. 2. †Assistant Professor, Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, UT. 3. §Department of Pediatric Pathology, University of Utah, Salt Lake City, UT. 4. ‡Professor, Department of Dermatology, University of Utah, Salt Lake City, UT. A 7-month-old boy presents to the pediatric infectious diseases clinic with an unusual rash for the past 4 weeks. The rash appeared first on the back of his neck as a reddish-brown raised “spot” (Fig. 1). Over the past month, other reddish-brown macules and papules have appeared on his anterior trunk that later have developed a fine scale, followed in some places by erosions and black eschar formation. These lesions were neither vesicular nor pustular in appearance before eroding. The eschars eventually healed, leaving hypopigmented scars. Figure 1. Reddish-brown raised “spot” on back of thigh similar to the “spot” that first appeared on the back of infant's neck. The infant has been asymptomatic otherwise and has gained weight during this time, maintaining his normal appetite and activity. There is no history of fever or discomfort. Initially, a pediatrician thought the infant had scabies and prescribed permethrin cream, but there was no improvement of the infant's condition. The pediatrician then prescribed two courses of antibiotics (cephalexin and amoxicillin) for a presumed varicella infection complicated by bacterial superinfection. Again, there was no improvement. Because of the continued appearance of new lesions the infant was referred to a pediatric infectious diseases clinic. The infant's past medical history is unremarkable. He was delivered vaginally without complications at term and has been healthy otherwise until the rash appeared. There has been no animal exposure or travel. There is no history of a respiratory or gastrointestinal infection or administration of any medications before the onset of the rash. His immunizations are up to date, and he does not have any allergies. The family history is …