[Allergic contact dermatitis to temporary henna tattoos].

INTRODUCTION In the last years there have been increasing reports of adverse cutaneous reactions to temporary black henna tattoos. Black henna does not exist naturally, it is obtained from original henna after the addition of other compounds, among them paraphenylenediamine (PPD), that darken it and facilitate the process of tattoing. Paraphenylenediamine is an aromatic compound that presents cross reactions with other components that have a benzene ring in their molecular structure. Many of these products may be present in the daily life of any person. MATERIAL AND METHODS We reviewed patients that have shown erythema, inflammation and/or vesiculation in a previously tattooed area. The patients have undergone a temporary tattoo in street stalls during the summer period (2004-2005). A total of five patients were included, there were four men and one woman with a mean age of 13 years (3-34) and a mean latency period of 9.4 days (5-14). Black ink and plastic stencils were used to perform the tattoo. None of the patients has had previous contact with hair dyes or tattoos and none of them referred a personal history of atopic dermatitis. Patch testing was carried out using the standard set of the Spanish Group for Research in Contact Dermatitis [GEIDC] (TRUE TEST, Pharmacia. Hillerod. Denmark), with readings at 48 and 96 hours. RESULTS Sensitization to PPD is confirmed in three patients, one of them was also sensitized to formaldehyde. Hypopigmented scars persist in three patients. CONCLUSIONS Black henna pseudotattoos are a source of sensitization to PPD with potential severe consequences in a medium to long term. Currently there is no specific legislation with respect to the practice of this type of tattoos in our country.