Learn about the potential risks associated with temporary black henna tattoos and the precautions that can help reduce the risk of allergic skin reactions.
During the summer months, it is common to see temporary tattoo stalls offering so-called black henna tattoos at beaches, seafront promenades, fairs and markets.
This practice has become sufficiently widespread for the Spanish Agency of Medicines and Medical Devices (AEMPS) to issue warnings and recommendations concerning these products. So-called black henna preparations can cause significant skin reactions, including itching, burning, inflammation, dermatitis and changes in pigmentation, as well as, in more severe cases, blistering and scarring.
One particular concern is their use in children and adolescents, who may be attracted by the fact that the designs are temporary and therefore appear harmless. Social-media trends involving temporary freckles and other skin designs have also encouraged the use of dark henna-type products on the face, where inappropriate formulations can cause significant skin reactions.
Black henna is not natural henna
Natural henna is a plant-derived dye obtained from the leaves of Lawsonia inermis.
The plant material is dried and ground into a powder, which is then mixed with liquid to form a paste.
Natural henna has traditionally been used to colour hair and decorate the skin, particularly the hands and feet, in social and religious traditions across regions including India, Pakistan, the Middle East and North Africa. When applied to the skin, natural henna produces a characteristic orange to reddish-brown stain that gradually darkens and then fades as the outer layers of the skin are shed.
So-called black henna is different. Commercial products marketed under this name may contain chemical additives intended to create a darker colour and shorten the time required for the design to develop. As Dr Rita Rodrigues, a Grupo Pedro Jaén specialist in sensitive skin and contact dermatitis, explains, one of the substances of greatest concern is p-phenylenediamine (PPD).
PPD is used in certain products, most notably some permanent oxidative hair dyes. It is a potent contact allergen and can penetrate the skin, particularly when used at inappropriate concentrations or left in prolonged contact with it. For this reason, direct application of high concentrations of PPD to the skin in temporary tattoo products can result in severe allergic contact dermatitis and sensitisation.
Risks of temporary black henna tattoos: PPD and cosmetic regulation
The use of p-phenylenediamine (PPD) in cosmetics is strictly regulated because of its sensitising potential. Its use is permitted only in specified cosmetic applications and under defined conditions. It is not intended for direct application to the skin as a temporary tattoo ingredient.
Despite these restrictions, black henna preparations containing substantial concentrations of PPD have been reported. High exposure can cause an intense inflammatory reaction and may lead to sensitisation not only to PPD itself but, in some cases, to structurally related substances.
Reactions can develop after the tattoo is applied and may occasionally be severe enough to require medical treatment or hospital assessment.
A particularly important long-term consequence is persistent sensitisation to PPD. Once allergic sensitisation has developed, subsequent exposure to PPD may trigger another reaction, sometimes more rapidly and intensely than the initial episode. This can be relevant later in life if the individual uses hair dye or encounters related substances. Cases have been reported in which children sensitised following black henna tattoos subsequently experienced severe reactions after exposure to PPD-containing hair dyes.
Other problems associated with p-phenylenediamine (PPD)
The potential consequences of PPD allergy are not limited to the reaction that occurs at the site of the original tattoo.
People who become allergic to PPD may also react to certain chemically related substances. The clinical relevance of these potential cross-reactions varies between individuals and should be assessed by a dermatologist or allergist.
This is one reason why a confirmed allergy to PPD should be documented in the patient’s medical history.
People with occupational exposure to dyes, inks, rubber chemicals or related substances may require particular advice if sensitisation is confirmed. This may be relevant, for example, to certain hairdressers and professionals working with dyes, printing products, textiles or other materials containing related compounds.
Advice on using henna products
Natural henna produces an orange, red or reddish-brown stain, rather than an intense black colour. For this reason, products marketed as ‘black henna’ or those that produce a very dark result unusually quickly should be treated with caution. Before using any henna-based cosmetic product, it is advisable to:
1. Check the ingredient list and labelling carefully. Avoid products intended for skin decoration if they contain PPD or if their composition is unclear.
2. Be particularly cautious with products sold at unregulated stalls, markets or through sources where the exact composition cannot be verified.
3. Do not assume that a temporary tattoo is harmless. Temporary contact with the skin can still result in allergic sensitisation.
4. Avoid black henna temporary tattoos in children, who may remain sensitised to PPD for many years after a single exposure.
5. Seek medical advice if a reaction occurs. Redness, itching, swelling, blistering or weeping at the tattoo site may indicate contact dermatitis.
If significant facial swelling, breathing difficulty or other severe symptoms occur, urgent medical assessment is required. Home testing of an unregulated black henna product on a small area of skin is not a reliable way of establishing that the product is safe. A lack of reaction to one application does not rule out subsequent sensitisation or allergy. When contact allergy is suspected, the appropriate diagnostic procedure is patch testing performed and interpreted by a specialist.
With regard to hair dyes, anyone with a known PPD allergy or a previous significant reaction to a black henna tattoo should seek specialist advice before using oxidative hair dyes.
References
1. José María Ortiz Salvador, Altea Esteve Martínez, Daniela Subiabre Ferrer, Ana Mercedes Victoria Martínez, Jesús de la Cuadra Oyanguren, Violeta Zaragoza Ninet. Dermatitis alérgica de contacto a parafenilendiamina por tatuajes con henna en población pediátrica. Anales de Pediatría, Volume 86, Issue 3, 2017, Pages 122-126, ISSN 1695-4033. https://doi.org/10.1016/j.anpedi.2016.02.010.
2. Encabo Durán B, Romero-Pérez D, Silvestre Salvador JF. Allergic Contact Dermatitis Due to Paraphenylenediamine: An Update. Actas Dermosifiliogr (Engl Ed). 2018 Sep;109(7):602-609. English, Spanish. doi: 10.1016/j.ad.2017.12.007. Epub 2018 Feb 26. PMID: 29496197.
3. Miquel Miquel FJ. Contact Allergy to Paraphenylenediamine: A Persistent Problem That Needs Stricter Regulation. Actas Dermosifiliogr (Engl Ed). 2020 Jan 2;111(1):1-2. English, Spanish. doi: 10.1016/j.ad.2019.07.004. Epub 2019 Dec 5. PMID: 31813473.
4. Trostiansky C, Le Guyadec T, Bellier S, Beylot V. Allergie de contact à la paraphénylènediamine [Paraphenylenediamine contact allergy]. Rev Prat. 2018 Jun;68(6):635. French. PMID: 30869253.
5. Diepgen TL, Naldi L, Bruze M, Cazzaniga S, Schuttelaar ML, Elsner P, Goncalo M, Ofenloch R, Svensson Å. Prevalence of Contact Allergy to p-Phenylenediamine in the European General Population. J Invest Dermatol. 2016 Feb;136(2):409-415. doi: 10.1016/j.jid.2015.10.064. PMID: 26802237.
6. Bacharewicz-Szczerbicka J, Reduta T, Pawłoś A, Flisiak I. Paraphenylenediamine and related chemicals as allergens responsible for allergic contact dermatitis. Arch Med Sci. 2019 Jul 18;17(3):714-723. doi: 10.5114/aoms.2019.86709. PMID: 34025842; PMCID: PMC8130485.
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