A review study of chemical constituents and side-effects of black henna for children

Henna (Lawsonia inermis) belongs to Lythraceae family is widely used in Islamic and Hindu cultures to dye their skin, hair, and nails. There are three different kinds of Henna: Red henna, neutral henna and black henna. Red henna dye the skin reddish-brown, neutral henna dye no color while Black henna (the combination of red henna with p-phenylenediamine (PPD)) is used for temporary 'black henna tattoos'. This article provides a full review of the side-effects of topical application of red and black henna, both cutaneous (allergic and non-allergic) and systemic on children. This review article was carried out by searching studies in PubMed, Medline, Web of Science, and Iran Medex databases up to 2015.totally, of 156 found articles,64articles were included. The search terms were "black henna"," side-effects", "children", "Lawsonia", "p-phenylenediamine". In children with glucose-6-phosphate dehydrogenase deficiency, topical application of henna may cause life-threatening hemolysis. Black henna tattoos will induce contact allergy to its ingredient PPD at an estimated frequency of 2.5%. Once sensitized, the patients may experience allergic contact dermatitis from the use of hair dyes containing PPD. Topical application of black henna was shown to trigger allergic, non-allergic and systemic side-effects including hemolysis, localized hypertrichosis, allergic contact dermatitis i.e. depigmented spots, itching, erythema, enduration, Erythematous, residual hypopigmentation, intense facial and scalp dermatitis in children. The sensitization of children to PPD may have important aftermath for their health and future life. Thus, its topical application should be forbidden by authorities.