Viral exanthems: an update.

Classic viral exanthems, such as measles, rubella, and Fifth disease, have great historical significance and, despite vaccine successes, still occur both in the United States and across the world. Because they are either less commonly seen (e.g., measles) or recognized by pediatricians (e.g., Fifth disease), viral exanthems that present to dermatology clinics are often "atypical" and may cause diagnostic confusion. This article will first review a general approach to the patient with a possible viral exanthem, discuss several current issues germane to "classic" exanthems, and delve into greater detail regarding atypical presentations.