Effect Of Henna

Indian Journal of Pharmacology 2002; 34: 436-437

ADVERSE REACTIONS TO HENNA The henna plant Lawsonia inermis Linn is a fragrant shrub native to Asia and northern Africa. The species is sometimes referred to as L. alba or L. rubra and is cultivated in India, the Middle East, Egypt and tropical America. Mehendi or henna dye is prepared by grinding the fresh leaves of this plant or by powdering the dried leaves and then mixing into a grayishgreen paste with water. The resulting brown dye is extensively used as decorative skin paint, for nail coloring and as hair dye and conditioner. The dye stays for a few weeks and then fades. The use of this natural cosmetic is a much-loved tradition in India dating back to antiquity. For instance, wedding ceremonies in many parts of the country would be incomplete without the ritual of creating intricate designs on the hands and feet of the bride with henna. Orthodox jews and muslims who shun synthetic colors use only henna as a natural paint and hair dye. The custom of using henna for paint-on tattooing is spreading, even in western countries. A casual enquiry from a dermatologist colleague prompted a literature search for potential toxic effects of henna. What emerged is worth sharing. Most numerous are reports of allergic contact dermatitis. These can occur in any user and manifest as eczematous, lichenoid or more severe reactions1. The dermatitis results from a contact hypersensitivity reaction and mostly remains restricted to the actual area of contact. There may be residual depigmentation for weeks or even scarification. Interestingly, pure natural henna per se rarely, if at all, causes contact hypersensitivity. In most cases, the reaction appears to be provoked by the addition of synthetic dyes like para-phenylenediamine (PPD), para-toluylenediamine, or related chemicals2. These are added to natural henna to darken the coloration and shorten application times. The resulting product is called black henna. Patch testing with PPD is often strongly positive in subjects showing allergic reaction to black henna tattooing. Similar sensitization is probably also responsible for chronic asthmatic reactions to henna following occupational exposure, such as in hairdressers. Immediate-type hypersensitivity reactions, possibly IgE mediated, manifesting as urticaria, rhinitis, and acute bronchospasm, have also been reported in hairdressers. Severe and fatal angioneurotic edema oc-

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Figure 1. 2-Hydroxy-1,4-naphthoquinone (lawsone), the entity responsible for hemolysis caused by henna in G6PD deficiency. The structure is closely related to 2-methyl-1,4-naphthoquinone (menadione), the water soluble parent vitamin K compound that can also cause hemolysis. However, menadione does not share the nephrotoxic activity of lawsone.

curred in a series of deliberate and accidental poisonings in children exposed to henna-PPD mixtures in Khartoum, Sudan3. Also serious are reports of life-threatening hemolytic crisis on topical exposure to henna in individuals deficient in glucose-6-phosphate dehydrogenase (G6PD). A recent case series reported 4 instances of such a reaction in G6PD-deficient children - a neonate, an infant and two pre-school children4. The hemolytic crisis was manifest within 24 - 72 hr of the henna application. The male infant could not be saved despite exchange transfusion. The culprit in this case appears to be the oxidizing agent 2-hydroxy-1,4naphthoquinone or lawsone ( Figure 1) which occurs naturally in henna and has been documented to cause dose-dependent hemolytic anemia and nephrotoxicity in laboratory rats5. Lawsone is the actual dye in henna. In addition to its extensive use as natural cosmetic, henna has some potential medical uses too. Henna extracts have shown fungistatic, bacteriostatic and anti-inflammatory activity. Lawsone may exert antisickling effects in sickle cell anemia. Allyl derivatives of lawsone, but not the parent compound, have shown activity against Trypanosma cruzi in vitro6. An interesting application of henna is as a durable skin-marking agent in patients undergoing external radiotherapy, especially during conformal techniques7. Accuracy is increased and bathing is permitted in this situation improving patient comfort. In view of the existing and potential uses of henna, practitioners should remain alert to adverse reactions. The use of black henna, in particular, needs to be

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informed and possibly restricted. Manufacturers should voluntarily declare whether or not their henna products are additive free. Adulteration must be prosecuted. Henna can be avoided in neonates and young children and in individuals known to be G6PD deficient. Potential mishaps may thus be curtailed.

4.

Raupp P, Hassan JA, Varughese M, Kristiansson B. Henna causes life threatening haemolysis in glucose-6-phosphate dehydrogenase deficiency. Arch Dis Child 2001;85:411-2.

5.

Munday R, Smith BL, Fowke EA. Haemolytic activity and nephrotoxicity of 2-hydroxy-1,4-naphthoquinone in rats. J Appl Toxicol 1991;11:85-90.

6.

Pinto AV, Pinto CN, Pinto Mdo C, Rita RS, Pezzella CA, de Castro SL. Trypanocidal activity of synthetic heterocyclic derivatives of active quinones from Tabebuia sp. Arzneimittelforschung 1997;47:74-9.

7.

Wurstbauer K, Sedlmayer F, Kogelnik HD. Skin markings in external radiotherapy by temporary tattooing with henna: Improvement of accuracy and increased patient comfort. Int J Radiat Oncol Biol Phys 2001;50:179-81.

REFERENCES 1.

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3.

Chung WH, Chang YC, Yang LJ, Hung SI, Wong WR, Lin JY, et al. Clinicopathologic features of skin reactions to temporary tattoos and analysis of possible causes. Arch Dermatol 2002;138:88-92. Le Coz CJ, Lefebvre C, Keller F, Grosshans E. Allergic contact dermatitis caused by skin painting (pseudotattooing) with black henna, a mixture of henna and p-phenylenediamine and its derivatives. Arch Dermatol 2000;136:1515-7. Sir Hashim M, Hamza YO, Yahia B, Khogali FM, Sulieman GI. Poisoning from henna dye and para-phenylenediamine mixtures in children in Khartoum. Ann Trop Paediatr 1992;12:3-6.

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AVIJIT HAZRA Department of Pharmacology, University College of Medicine, Calcutta Univesity, 244B Acharya J.C. Bose Road, Calcutta - 700 020. e-mail: [email protected]

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