[A boy with a skin lesion after a henna tattoo].

An 11-year-old boy got a temporary black henna tattoo while on vacation. After 3 days he developed an itching rash at the site of the tattoo, that spread to the rest of the body. This was most likely an allergic contact dermatitis and erythema exsudativum multiforme minor caused by the often high concentrations of the strong sensitizer para-phenylenediamine (PPD) in the henna.