All that is vesicular is not herpes: incontinentia pigmenti masquerading as herpes simplex virus in a newborn.

Incontinentia pigmenti is a multisystem genodermatosis characterized by cutaneous, neurologic, ophthalmologic, and dental abnormalities. The skin lesions associated with the disease progress through 4 stages, the first being erythematous vesicles linearly distributed along the lines of Blaschko. We report a case of an infant who had incontinentia pigmenti and presented with 2 crops of vesicles and was initially thought to have herpes simplex virus.