Picture of Allergic Contact Dermatitis (Tattoo)
Allergic contact dermatitis is a skin reaction that occurs when the skin comes into contact with a compound that provokes a reaction. It is possible to react to compounds in temporary tattoo material. Temporary tattoos contain a mixture of brown henna and black henna, which contains paraphenylenediamine (PPD). The allergic reactiony results from the PPD in the temporary tattoo. The first sign of the condition is a skin eruption that resembles eczema. The affected area may appear hyperpigmented for some time after the exposure.
Text Reference: American College of Allergy, Asthma, & Immunology: "Contact Dermatitis"