A number of different widespread and disseminated viral infections can occur in patients with atopic dermatitis. Eczema molluscatum is troublesome but not dangerous. Although eczema vaccinatum is rare, it is life-threatening and of increased concern as smallpox vaccinations are reintroduced as a response to possible bioterrorism. There is little information on the course of smallpox itself in atopic dermatitis. Eczema herpeticum is the most common member of this group; recent advances in understanding its pathogenesis might contribute to a more successful management of this serious complication.