Visual diagnosis: 12-month-old boy with persistent rash and lymphadenopathy.

Gianotti-Crosti syndrome (GCS) is a self-limiting, papular or papulovesicular, symmetric, acral exanthem that typically presents subsequent to viral infection, bacterial infection, or immunization in a child 1 to 4 years old. The rash can persist for 2 to 10 weeks. Recent infection with Epstein-Barr virus is the most common serologic finding in patients who have developed GCS. The diagnosis is often made after the child has been unsuccessfully treated for a more common cause of an acral rash (eg, scabies). There are no pathognomonic laboratory or histopathologic findings. GCS, therefore, is still a clinical diagnosis of exclusion. The rash is self-limited, and treatment is usually not necessary. However, topical corticosteroids are anecdotally reported to reduce duration of rash. Oral antihistamines can be used to treat pruritus. Parents should be assured that resolution is almost always complete, scarring seldom occurs, and recurrence is rare.