||This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. (November 2012)|
Henna (Lawsonia inermis, also known as hina, the henna tree, the mignonette tree, and the Egyptian privet) is a flowering plant and the sole species of the Lawsonia genus. The English name "henna" comes from the Arabic حِنَّاء (ALA-LC: ḥinnāʾ; pronounced [ħɪnˈnæːʔ]) or, colloquially حنا, loosely pronounced as /ħinna/.
The name henna also refers to the dye prepared from the plant and the art of temporary tattooing based on those dyes. Henna has been used since antiquity to dye skin, hair, and fingernails, as well as fabrics including silk, wool, and leather. The name is mistakenly used in other skin and hair dyes, such as black henna and neutral henna, neither of which are derived from the henna plant.
Henna is a tall shrub or small tree, standing 1.8 to 7.6 m (5 ft 10 in to 24 ft 10 in) tall. It is glabrous and multi-branched, with spine-tipped branchlets. The leaves grow opposite each other on the stem and are glabrous, sub-sessile, elliptical, and lanceolate (long and wider in the middle; average dimensions are 1.5–5.0 cm x 0.5–2 cm or 0.6–2 in x 0.2–0.8 in), acuminate (tapering to a long point), and have depressed veins on the dorsal surface. Henna flowers have four sepals and a 2 mm (0.079 in) calyx tube with 3 mm (0.12 in) spread lobes. Its petals are obvate, with white or red stamens found in pairs on the rim of the calyx tube. The ovary is four-celled, 5 mm (0.20 in) long, and erect. Henna fruits are small, brownish capsules, 4–8 mm (0.16–0.31 in) in diameter, with 32–49 seeds per fruit, and open irregularly into four splits.
The henna plant is native to northern Africa, western and southern Asia, and northern Australasia in semi-arid zones and tropical. It produces the most dye when grown in temperatures between 35 and 45 °C (95 and 113 °F). During the onset of precipitation intervals, the plant grows rapidly; putting out new shoots, then growth slows. The leaves gradually yellow and fall during prolonged dry or cool intervals. It does not thrive where minimum temperatures are below 11 °C. Temperatures below 5 °C will kill the henna plant.
Henna has been used since the Bronze Age to dye skin (including body art), hair, fingernails, leather, silk and wool. In several parts of the world it is traditionally used in various festivals and celebrations. There is mention of henna as a hair dye in Indian court records around 400 CE, in Rome during the Roman Empire, and in Spain during Convivencia. It was listed in the medical texts of the Ebers Papyrus (16th-century BCE Egypt) and by Ibn Qayyim al-Jawziyya (14th century CE (Syria and Egypt) as a medicinal herb. In Morocco, wool is dyed and ornamented with henna, as are drumheads and other leather goods.
Use of henna for body art has enjoyed a recent renaissance due to improvements in cultivation, processing, and the emigration of people from traditional henna-using regions.
For skin dyeing, a paste of ground henna (either prepared from a dried powder or from fresh ground leaves) is placed in contact with the skin from a few hours to overnight. Henna stains can last a few days to a month depending on the quality of the paste, individual skin type, and how long the paste is allowed to stay on the skin.
Henna also acts as an anti-fungal and a preservative for leather and cloth.
Henna flowers have been used to create perfume since ancient times, and henna perfume is experiencing a resurgence. Henna repels some insect pests and mildew.
Henna's coloring properties are due to lawsone, a burgundy organic compound that has an affinity for bonding with protein. Lawsone is primarily concentrated in the leaves, especially in the petioles of the leaf. Lawsone content in leaves is negatively correlated with the number of seeds in the fruits.
Preparation and application 
Body art 
Whole, unbroken henna leaves will not stain the skin. Henna will not stain skin until the lawsone molecules are made available (released) from the henna leaf. Fresh henna leaves will stain the skin if they are smashed with a mildly acidic liquid. The lawsone will gradually migrate from the henna paste into the outer layer of the skin and bind to the proteins in it, creating a fast stain.
Since it is difficult to form intricate patterns from coarse crushed leaves, henna is commonly traded as a powder made by drying, milling and sifting the leaves. The dry powder is mixed with lemon juice, strong tea, or other mildly acidic liquids to make a preparation with toothpaste-like consistency, which can be used to make finely detailed body art. The henna mix must rest for 6 to 24 hours before use, to release the lawsone from the leaf matter. Essential oils with high levels of monoterpene alcohols such as tea tree, eucalyptus, cajeput, or lavender will improve skin stain characteristics.
The paste can be applied with many traditional and innovative tools, including resist, a cone, syringe, Jac bottle or fingers. A light stain may be achieved within minutes, the longer the paste is left on the skin, the stronger the stain will be, and should be left for several hours. To prevent it from drying or falling off the skin, the paste is often sealed down by dabbing a sugar/lemon mix over the dried paste, or simply adding some form of sugar to the paste. It is debatable whether this adds to the color of the end result; some believe it increases the intensity of the shade. After time the dry paste is simply brushed or scraped away.
Henna stains are orange soon after application, but darken over the following three days to a reddish brown. Soles and palms have the thickest layer of skin and so take up the most lawsone, and take it to the greatest depth, so that hands and feet will have the darkest and most long-lasting stains. Steaming or warming the henna pattern will darken the stain, either during the time the paste is still on the skin, or after the paste has been removed. Chlorinated water and soaps may spoil the darkening process: alkaline products may hasten the darkening process. After the stain reaches its peak color it will appear to fade, as the stained dead cells exfoliate.
Hair dye 
Henna has been used as a cosmetic hair dye for 6,000 years. In Ancient Egypt, henna was known to have been used. It was commonly used for many centuries in areas of India, the Middle East, and Africa.
In Ancient Egypt, Ahmose-Henuttamehu (17th Dynasty, 1574 BCE): Henuttamehu was probably a daughter of Seqenenre Tao and Ahmose Inhapy. Smith reports that the mummy of Henuttamehu's own hair had been dyed a bright red at the sides, probably with henna.
In Europe, henna was popular among women connected to the aesthetic movement and the Pre-Raphaelite artists of England in the 1800s. The fashion for Orientalism led young women with a bohemian inclination to begin tinting their hair with henna. Dante Gabriel Rossetti's wife and muse, Elizabeth Siddal, had naturally bright red hair. Contrary to the cultural tradition in Britain that considered red hair unattractive, the Pre-Raphaelites fetishized red hair. Siddal was portrayed by Rossetti in many paintings that emphasized her flowing red hair. The other Pre-Raphaelites, including Evelyn De Morgan and Frederick Sandys, academic classicists such as Frederic Leighton, and French painters such as Gaston Bussière and the Impressionists further popularized the association of henna-dyed hair and young bohemian women.
Opera singer Adelina Patti is sometimes credited with popularizing the use of henna in Europe in the late 1800s. Parisian courtesan Cora Pearl was often referred to as La Lune Rousse (the red moon) for dying her hair red. In her memoirs, she relates an incident when she dyed her pet dog's fur to match her own hair. By the 1950s, Lucille Ball popularized "henna rinse" as her character, Lucy Ricardo, called it on the television show I Love Lucy. It gained popularity among young people in the 1960s through growing interest in Eastern cultures.
Muslim men may use henna as a dye for hair and most particularly their beards. This is considered a sunnah, a commendable tradition of the Prophet Muhammad. Furthermore, a hadith (narration of the Prophet) holds that he encouraged Muslim women to dye their nails with henna to demonstrate femininity and distinguish their hands from the hands of men; thus some Muslim women in the Middle East apply henna to their finger and toenails as well as their hands.
Commercially packaged henna, intended for use as a cosmetic hair dye, is available in many countries, and is now popular in India, as well as the Middle East, Europe, Australia, Canada and the United States. The color that results from dying with henna depends on the original color of the hair, as well as the quality of the henna, and can range from orange to auburn to burgundy. Henna can be mixed with other natural hair dyes including Cassia Obovata for lighter shades of red or even blond, or with indigo to achieve brown and black shades. Some products sold as "henna" include these other natural dyes. Others may include metal salts that can interact with other chemical treatments, or oils and waxes that may inhibit the dye, or even chemical dyes which are common allergens. Any product that comes in a cream, block, or paste form has some sort of additives.
As with henna in body art, the dried leaf powder should be mixed with a mild acid such as lemon juice, orange juice, or vinegar and left to stand. The resulting paste is then applied to the hair, and covered with plastic wrap to keep it from drying out. This paste should be left in the hair for several hours in order for the dye to permanently bind to the hair strands. The paste is then washed away leaving hair that is permanently dyed. Sometimes henna is mixed with hot or boiling boiling water and used immediately. This gives a color that may fade, and which is not as rich or deep.
Traditions of henna as body art 
The different words for henna in ancient languages imply that it had more than one point of discovery and origin, as well as different pathways of daily and ceremonial use.
Henna has been used to adorn young women's bodies as part of social and holiday celebrations since the late Bronze Age in the eastern Mediterranean. The earliest text mentioning henna in the context of marriage and fertility celebrations comes from the Ugaritic legend of Baal and Anath, which has references to women marking themselves with henna in preparation to meet their husbands, and Anath adorning herself with henna to celebrate a victory over the enemies of Baal.
Wall paintings excavated at Akrotiri (dating prior to the eruption of Thera in 1680 BCE) show women with markings consistent with henna on their nails, palms and soles, in a tableau consistent with the henna bridal description from Ugarit. Many statuettes of young women dating between 1500 and 500 BCE along the Mediterranean coastline have raised hands with markings consistent with henna. This early connection between young, fertile women and henna seems to be the origin of the Night of the Henna, which is now celebrated worldwide.
The Night of the Henna was celebrated by most groups in the areas where henna grew naturally: Jews, Muslims,Sikhs, Hindus, Christians and Zoroastrians, among others, all celebrated marriages by adorning the bride, and often the groom, with henna.
Across the henna-growing region, Purim, Eid, Diwali, Karva Chauth, Passover, Nowruz, Mawlid, and most saints' days were celebrated with some henna. Favorite horses, donkeys, and salukis had their hooves, paws, and tails hennaed. Battle victories, births, circumcision, birthdays, Zār, as well as weddings, usually included some henna as part of the celebration. When there was joy, there was henna, as long as henna was available.
Henna was regarded as having "Barakah," blessings, and was applied for luck as well as joy and beauty. Brides typically had the most henna, and the most complex patterns, to support their greatest joy, and wishes for luck. Some bridal traditions were very complex, such as those in Yemen, where the Jewish bridal henna process took four or five days to complete, with multiple applications and resist work.
The fashion of "Bridal Mehndi" in Pakistan, Northern Libya and in North Indian diasporas is currently growing in complexity and elaboration, with new innovations in glitter, gilding, and fine-line work. Recent technological innovations in grinding, sifting, temperature control, and packaging henna, as well as government encouragement for henna cultivation, have improved dye content and artistic potential for henna.
Though traditional henna artists were Nai caste in India, and barbering castes in other countries (lower social classes), talented contemporary henna artists can command high fees for their work. Women in countries where women are discouraged from working outside the home can find socially acceptable, lucrative work doing henna. Morocco, Mauritania, Yemen, Libya, Somalia, Sudan, as well as India and many other countries have thriving women's henna businesses. These businesses are often open all night for Eid, Diwali and Karva Chauth. Many women may work together during a large wedding, wherein hundreds of guests have henna applied to their body parts. This particular event at a marriage is known as the Mehndi Celebration or Mehndi Night, and is mainly held for the bride and groom.
Health effects 
Henna is known to be dangerous to people with glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency), which is more common in males than females. Infants and children of particular ethnic groups are especially vulnerable. Though user accounts cite few other negative effects of natural henna paste, save for occasional allergic reactions, pre-mixed henna body art pastes may have ingredients added to darken stain, or to alter stain color. The health risks involved in pre-mixed paste can be significant. The United States Food and Drug Administration (FDA) does consider these risks to be adulterants and therefore illegal for use on skin. Some pastes have been noted to include: silver nitrate, carmine, pyrogallol, disperse orange dye, and chromium. These have been found to cause allergic reactions, chronic inflammatory reactions, or late-onset allergic reactions to hairdressing products and textile dyes.
The FDA has not approved henna for direct application to the skin. It is unconditionally approved as a hair dye, and can only be imported for that purpose. Henna imported into the U.S. which appears to be for use as body art is subject to seizure, though prosecution is rare.
"Neutral henna" and "black henna" 
Natural henna stains only a rich red brown. Products sold as "black henna" or "neutral henna" do not contain henna, but are instead made from other plants, or from other substances altogether.
"Neutral henna" 
So-called "neutral henna" does not change the color of hair. This is not henna powder; it is usually the powder of the plant Senna italica (often referred to by the synonym Cassia obovata) or closely related Cassia and Senna species.
"Black henna" 
So-called "black henna" powder may be derived from indigo (from the plant Indigofera tinctoria). It may also contain unlisted dyes and chemicals. "Black henna" may contain p-phenylenediamine (PPD), which can stain skin black quickly, but can cause severe allergic reactions and permanent scarring. The FDA specifically forbids PPD to be used for that purpose, and may prosecute those who produce "black henna'. Artists who injure clients with "Black Henna" in the U.S. may be sued for damages.
"Black Henna" is a misnomer arising from imports of plant-based hair dyes into the West in the late 19th century. Partly fermented, dried indigo was called "black henna" because it could be used in combination with henna to dye hair black. This gave rise to the belief that there was such a thing as "black henna" which could dye skin black. Indigo will not dye skin black. Pictures of indigenous people with black body art (either alkalized henna or from some other source) also fed the belief that there was such a thing as "black henna."
In the 1990s, henna artists in Africa, India, Bali, the Arabian Peninsula and the West began to experiment with para-phenylenediamine (PPD) based black hair dye, applying it as a thick paste as they would apply henna, in an effort to find something that would quickly make jet black temporary body art. PPD can cause severe allergic reactions, with blistering, intense itching, permanent scarring, and permanent chemical sensitivities. Estimates of allergic reactions range between 3% and 15%. Henna does not cause these injuries. "Black henna" made with PPD can cause lifelong sensitization to coal tar derivatives. "Black henna" made with gasoline, kerosene, lighter fluid, paint thinner, and benzene has been linked to adult leukemia.
The most frequent serious health consequence of having a "black henna temporary tattoo" is sensitization to hair dye and related chemicals. If a person has had a "black henna tattoo", and later dyes their hair with chemical hair dye, the allergic reaction may be life threatening and require hospitalization. Because of the epidemic of para-phenylenediamine allergic reactions, chemical hair dye products now post warnings on the labels: "Temporary 'black henna' tattoos may increase your risk of allergy. Do not colour your hair if: ... – you have experienced a reaction to a temporary 'black henna' tattoo in the past."
Para-phenylenediamine is illegal for use on skin in western countries, though enforcement is difficult. Physicians have urged governments to legislate against "black henna" because of the frequency and severity of injuries, especially to children. To assist prosecution of vendors, government agencies encourage citizens to report injuries and illegal use of "PPD black henna". When used in hair dye, the PPD amount must be below 6%, and application instructions warn that the dye not touch the scalp and the dye must be quickly rinsed away. "Black henna" pastes have PPD percentages from 10% to 80%, and are left on the skin for half an hour.
Para-phenylenediamine "black henna" use is widespread, particularly in tourist areas. Because the blistering reaction appears 3 to 12 days after the application, most tourists have left and do not return to show how much damage the artist has done. This permits the artists to continue injuring others, unaware they are causing severe injuries. The high profit margins of "black henna" and the demand for body art that emulates "tribal tattoos" further encourage artists to deny the dangers.
It is not difficult to recognize and avoid para-phenylenediamine "black henna":
- if a paste stains torso skin black in less than ½ hour, it has PPD in it.
- if the paste is mixed with peroxide, or if peroxide is wiped over the design to bring out the color, it has PPD in it.
Anyone who has an itching and blistering reaction to a black body stain should go to a doctor, and report that they have had an application of para-phenylenediamine to their skin.
PPD sensitivity is lifelong. A person who has become sensitized through "black henna tattoos" may have future allergic reactions to perfumes, printer ink, chemical hair dyes, textile dye, photographic developer, sunscreen and some medications. A person who has had a "black henna tattoo" should consult their physician about health consequences of para-phenylenediamine sensitization.
See also 
- Achiote (urucum, annatto), another plant that stains skin orange-red
- Genipapo, a plant that stains the skin blue-black
- Bailey first=L.H.; Bailey, E.Z (1976). Hortus Third: A concise dictionary of plants cultivated in the United States and Canada. New York: Macmillan. ISBN 978-0025054707.
- "Henna". HowStuffWorks. Retrieved 5 May 2013.
- Cartwright-Jones, Catherine (2004). "Cassia Obovata". Henna for Hair. Retrieved 5 May 2013.
- Dennis, Brady (26 March 2013). "FDA: Beware of "black henna" tattoos". The Style Blog. The Washington Post. Retrieved 5 May 2013.
- Kumar S., Singh Y. V., & Singh, M. (2005). "Agro-History, Uses, Ecology and Distribution of Henna (Lawsonia inermis L. syn. Alba Lam)". Henna: Cultivation, Improvement, and Trade. Jodhpur: Central Arid Zone Research Institute. pp. 11–12. OCLC 124036118.
- "henna (plant)". Encyclopedia Britannica. Retrieved 5 May 2013.
- Bechtold, Thomas; Mussak, Rita (6 April 2009). Handbook of Natural Colorants. John Wiley & Sons. p. 155. ISBN 9780470744963.
- Auboyer, Jeannine (2002) . Daily life in ancient India: from 200 BCE to 700 AD. London: Phoenix. ISBN 978-1-84212-591-5. OCLC 50577157.[page needed]
- Fletcher R. (1992). Moorish Spain. New York City: Henry Holt and Company. ISBN 978-0-8050-2395-4. OCLC 25834208.[page needed]
- Bryan, Cyril P.; G. Elliot Smith (1974) . Ancient Egyptian medicine: the Papyrus Ebers. Chicago: Ares Publishers. ISBN 978-0-89005-004-0. OCLC 247258585.[page needed]
- Ibn Qayyim al-Jawzīyah, Muhammad ibn Abī Bakr (1998). Medicine of the prophet. trans. Penelope Johnstone. Cambridge: Islamic Texts Society. ISBN 978-0-946621-19-4. OCLC 40907417.[page needed]
- Roy, P. K., Singh, M., & Tewari, P. (2005). "Composition of Henna Powder, Quality Parameters and Changing Trends in its Usage". Henna: Cultivation, Improvement, and Trade. Jodhpur: Central Arid Zone Research Institute. pp. 39–40. OCLC 124036118.
- Bosoglu A, Birdane F, Solmaz H (1998). "The effect of Henna (Folium lawsoniae) paste in ringworm in calves". Indian Veterinary Journal 75 (1): 83–84. ISSN 0019-6479.
- Singh, M., Jindal, S. K., & Singh, D. (2005). "Natural Variability, Propagation, Phenology and Reproductive Biology of Henna". Henna: Cultivation, Improvement, and Trade. Jodhpur: Central Arid Zone Research Institute. pp. 13–18. OCLC 124036118.
- G. Elliott Smith, The Royal Mummies, Duckworth Publishing; (September, 2000)
- Kortsch, Christine Bayles (2009). Dress Culture In Late Victorian Womens' Fiction. Ashgate. p. 81. ISBN 978-0-7546-6510-6.
- "Aesthetics". Retrieved 15 August 2011.
- Pearl, Cora (2009). The Memoirs of Cora Pearl 13. General Books LLC. pp. 978–1151590527. ISBN ISBN 1151590525. Unknown parameter
- Sherrow, Victoria (2006). Encyclopedia of Hair: A Cultural History. Greenwood. pp. 206–207. ISBN ISBN 0313331456 ISBN 978-0-313-33145-9 Check
- Cartwright-Jones, Catherine. Henna for Hair. Free E-Book.
- de Moor, Johannes C. (1971). The seasonal pattern in the Ugaritic myth of Balu, according to the version of Ilimilku, (Alter Orient und Altes Testament). Kevelaer: Butzon & Bercker. ISBN 978-3-7887-0293-9. OCLC 201316.[page needed]
- D̲oumas, Christos (1992). The wall-paintings of Thera. Athens: Thera Foundation. ISBN 978-960-220-274-6. OCLC 30069766.[page needed]
- Brauer, Erich; Raphael Patai (1993). The Jews of Kurdistan. Detroit: Wayne State University Press. ISBN 978-0-8143-2392-2. OCLC 27266639.[page needed]
- Westermarck, Edward (1972) . Marriage ceremonies in Morocco. London: Curzon Press. ISBN 978-0-87471-089-2. OCLC 633323.[page needed]
- Hammoudi, Abdellah (1993). The victim and its masks: an essay on sacrifice and masquerade in the Maghreb. Chicago: University of Chicago Press. ISBN 978-0-226-31525-6. OCLC 27265476.[page needed]
- Saksena, Jogendra (1979). Art of Rajasthan: Henna and Floor Decorations. Delhi: Sundeep. OCLC 7219114.[page needed]
- Westermarck, E. (1926). Ritual and Belief in Morocco Vols 1 & 2. London, UK: Macmillan and Company, Limited[page needed]
- Tauzin, Aline (1998). Le henné, art des femmes de Mauritanie. Paris: UNESCO. ISBN 978-92-3-203487-8. Unknown parameter
|isbn-status=ignored (help)[page needed]
- "Henna and Glucose-6-phosphate dehydrogenase deficiency". The Henna Page.
- "Temporary Tattoos & Henna/Mehndi". Food and Drug Administration.
- Kang IJ, Lee MH (July 2006). "Quantification of para-phenylenediamine and heavy metals in henna dye". Contact Dermatitis 55 (1): 26–9. doi:10.1111/j.0105-1873.2006.00845.x. PMID 16842550.
- Dron P, Lafourcade MP, Leprince F, et al. (June 2007). "Allergies associated with body piercing and tattoos: a report of the Allergy Vigilance Network". European Annals of Allergy and Clinical Immunology 39 (6): 189–92. PMID 17713170.
- Raupp P, Hassan JA, Varughese M, Kristiansson B (November 2001). "Henna causes life threatening haemolysis in glucose-6-phosphate dehydrogenase deficiency". Archives of Disease in Childhood 85 (5): 411–2. doi:10.1136/adc.85.5.411. PMC 1718961. PMID 11668106.
- "§ 73.2190 Henna". Listing of Color Additives Exempt from Certification. Federal Register. 30 July 2009. Retrieved 3 August 2009.
- Singh, M., Jindal, S. K., Kavia, Z. D., Jangid, B. L., & Khem Chand (2005). "Traditional Methods of Cultivation and Processing of Henna. Henna, Cultivation, Improvement and Trade". Henna: Cultivation, Improvement, and Trade. Jodhpur: Central Arid Zone Research Institute. pp. 21–24. OCLC 124036118.
- Van den Keybus C., Morren M.A., Goossens A. (September 2005). "Walking difficulties due to an allergic reaction to a temporary tattoo". Contact Dermatitis 53 (3): 180–1. doi:10.1111/j.0105-1873.2005.0407m.x. PMID 16128770.
- Stante M, Giorgini S, Lotti T (April 2006). "Allergic contact dermatitis from henna temporary tattoo". Journal of the European Academy of Dermatology and Venereology 20 (4): 484–6. doi:10.1111/j.1468-3083.2006.01483.x. PMID 16643167.
- Jung P., Sesztak-Greinecker G., Wantke F., Götz M., Jarisch R., Hemmer W. (April 2006). "A painful experience: black henna tattoo causing severe, bullous contact dermatitis". Contact Dermatitis 54 (4): 219–20. doi:10.1111/j.0105-1873.2006.0775g.x. PMID 16650103.
- Lifelong damage from black henna, Hennapage.com
- Acute leukemia among the adult population of United Arab Emirates: an epidemiological study. 2009, vol. 50, no. 7, pp. 1138–1147. Inaam Bashir Hassan, Sherief I. A. M. Islam, Hussain Alizadeh, Jorgen Kristensen, Amr Kamba, Shanaaz Sonday and Roos M. D. Bernseen.
- Severe allergic hair dye reactions in 8 children. Heidi Sosted1,Jeanne Duus Johansen, Klaus Ejner Andersen, Torkil Menné, Contact Dermatitis, Volume 54, Issue 2, pages 87–91, February 2006
- Commission Directive 2009/134/EC of 28 October 2009 amending Council Directive 76/768/EEC concerning cosmetic products for the purposes of adapting Annex III thereto to technical progress
- "p-Phenylenediamine in Black Henna Tattoos A Practice in Need of Policy" in Children Sharon E. Jacob, MD; Tamar Zapolanski, BA; Pamela Chayavichitsilp, BA; Elizabeth Alvarez Connelly, MD; Lawrence F. Eichenfield, MD Arch Pediatr Adolesc Med. 2008;162(8):790–792.
- Kang IJ, Lee MH. Quantification of para-phenylenediamine and heavy metals in henna dye. Contact Dermatitis 2006;55:26–9.
- "Acute fingertip dermatitis from a temporary tattoo and quantitative chemical analysis of the product" Avnstorp, C., Rastogi, S., and Menne, T. Contact Point, 2002, p. 119
- Marcoux, D.; Couture-Trudel, P.; Riboulet-Delmas, G.; Sasseville, D. 2002. Sensitization to Para-Phenylenediamine from a Streetside Temporary Tattoo. Pediatric Dermatology 19, 6:498–502.
- Onder, M. 2003. Temporary holiday "tattoos" may cause lifelong allergic contact dermatitis when henna is mixed with PPD. Journal of Cosmetic Dermatology 2, 3–4: 126–130.
- Önder, Meltem, Çiğdem Asena Atahan, Pinar Öztaş, and Murat Orhan Öztaş. 2001. Temporary henna tattoo reactions in children. International Journal of Dermatology 40, 9: 577–579.
- Truetest.com[dead link]
|Wikimedia Commons has media related to: Mehndi|
|Wikimedia Commons has media related to: Henna|
|Look up henna in Wiktionary, the free dictionary.|