Incontinentia pigmenti (IP) is a rare X-linked dominant multi-systemic ectodermal dysplasia usually lethal in males and presenting neonatally in females with a bullous rash along Blashko's lines (BL) followed by verrucous plaques evolving over time to hyperpigmented swirling patterns. It is further characterized by teeth abnormalities, alopecia, nail dystrophy and affects occasionally the retina and the central nervous system (CNS).

An inflammatory process in skin caused by an exogenous agent that directly or indirectly injure the skin. If the offending agent is identified and removed, the eruption will resolve. An unusual or patterned eruption may be a clue to the presence of a contact dermatitis. Patch testing may be helpful in the differential diagnosis.