In the last 2 years, attention has been drawn to the use of p-phenylenediamine (PPD) in henna dyes and the potential for this allergenic chemical to cause hyper sensitivity reactions.1,2p-Phenylenediamine is an oxidative chemical that is frequently used as a permanent hair-coloring agent. It is added to henna to increase the intensity and longevity of the tattoo and expedites its drying time.3,4 Henna itself is a greenish brown vegetable coloring made from the leaves of Lawsonia inermis and rarely causes allergic contact dermatitis (Figure 1).5 The addition of PPD causes the contact sensitization to black henna (Figure 2).
Jacob SE, Zapolanski T, Chayavichitsilp P, Connelly EA, Eichenfield LF. p-Phenylenediamine in Black Henna TattoosA Practice in Need of Policy in Children. Arch Pediatr Adolesc Med. 2008;162(8):790-792. doi:10.1001/archpedi.162.8.790