Crawling Toward a Diagnosis: Vesicles and Thrombocytopenia in a Neonate.

C A S E A previously healthy 25-day-old boy presented to a tertiary children’s hospital with a diffuse vesicular rash worsening over the previous 2 weeks. Per parental report, the rash was not accompanied by any other symptoms and did not appear to be pruritic or painful; specifically, he had no history of fever and was formula feeding well. The infant was the product of a full-term pregnancy, complicated only by a maternal diagnosis of pruritic papules and plaques of pregnancy at ∼34 weeks of gestation. There was no known maternal history of herpes simplex virus (HSV) infection, and the mother denied any recent personal or family history of rashes or other skin lesions. The infant did not have any known allergies and no offending topical agent could be identified from the parental interview. He was not taking any medications.