Chemical information

Henna Leaf; Henné; Lawsonia.


Henna is the dried leaves of Lawsonia inermis (L. alba) (Lythraceae), containing lawsone. Powdered henna is used for dyeing the hair, skin, and nails.

Adverse effects.

Allergic skin reactions to henna used to dye the skin have been reported.1 Such reactions were usually due to additives used to shorten the application time of the dye and allergic reactions to ‘plain’ henna were rare. Similar reactions have been reported2-10 after henna tattoos on the skin. The adulterant, which is added to natural henna to darken it (‘black henna’), was identified2,5 as paraphenylenediamine. There have been reports of the paraphenylenediamine adulterant producing permanent skin pigment changes7,10 and also cross-sensitisation to paraphenylenediamine-containing hair dyes7-10 and textile dyes;10 there is also the possibility of sensitisation to other allergens such as natural rubber latex.10 The suggestion that henna may cause neonatal hyperbilirubinaemia is discussed under Lawsone.
1. Lestringant GG, et al. Cutaneous reactions to henna and associated additives. Br J Dermatol 1999; 141: 598–600
2. Brancaccio RR, et al. Identification and quantification of paraphenylenediamine in a temporary black henna tattoo. Am J Contact Dermat 2002; 13: 15–8
3. Marcoux D, et al. Sensitization to para-phenylenediamine from a streetside temporary tattoo. Pediatr Dermatol 2002; 19: 498–502.
4. Neri I, et al. Childhood allergic contact dermatitis from henna tattoo. Pediatr Dermatol 2002; 19: 503–5
5. Bowling JC, Groves R. An unexpected tattoo. Lancet 2002; 359: 649
6. Leggiadro RJ, et al. Temporary tattoo dermatitis. J Pediatr 2003; 142: 586
7. Matulich J, Sullivan J. A temporary henna tattoo causing hair and clothing dye allergy. Contact Dermatitis 2005; 53: 33–6
8. Sosted H, et al. Severe allergic hair dye reactions in 8 children. Contact Dermatitis 2006; 54: 87–91
9. Redlick F, DeKoven J. Allergic contact dermatitis to paraphenylendiamine in hair dye after sensitization from black henna tattoos: a report of 6 cases. CMAJ 2007; 176: 445–6
10. Sonnen G. Type IV hypersensitivity reaction to a temporary tattoo. Proc (Bayl Univ Med Cent) 2007; 20: 36–8.
Published May 08, 2019.