Irritant contact dermatitis from a black henna tattoo without sensitization to para-phenylendiamine.

Allergic contact dermatitis from nonpermanent black henna tattoos has been frequently reported, particularly in children. Contamination or adulteration of the dyes with para-phenylendiamine has been identified as major cause of active sensitization and elicitation of severe allergic contact dermatitis. Sequelae include permanent sensitization, hyper- or hypopigmentation, scarring, keloids, and hypertrichosis. We report a rare case of irritant dermatitis to an unknown ingredient in a black henna tattoo with consecutive hypopigmentation. Sensitization to para-phenylendiamine and other para-compounds was excluded by patch test evaluation. This is relevant for future exposure to consumer products such as hair dyes or in occupational settings. Generally, black henna tattoos, particularly if done with dyes of unknown composition, should be strongly discouraged.