Allergic Contact Dermatitis to a Temporary Henna Tattoo

A 23-year-old healthy Somali woman presented at our hospital in Nairobi, Kenya, with firm blisters on both forearms that appeared 48 h after applying a henna tattoo for a traditional wedding (Figure 1 A,B). She had experienced similar, albeit milder, symptoms following a henna tattoo application 2 years prior, which had resolved spontaneously. The distinct history and clinical presentation led to the diagnosis of allergic contact dermatitis to para-phenylenediamine (PPD). Treatment involved topical corticosteroids. Epicutaneous patch testing was not available nor affordable in our setting.

PPD is a potent sensitizer commonly found in hair and textile dyes and is increasingly used in temporary henna tattoos to extend longevity, expedite the drying process and intensify the colouring [1]. The patient's re-exposure to PPD triggered a delayed-type hypersensitivity reaction. Henna is a natural dye derived from the Lawsonia inermis plant and is a weak sensitizer. It has been used for centuries in Africa, Asia and the Middle East for medicinal and decorative purposes and typically lasts 5−7 days [2]. The increasing popularity of long-lasting temporary henna tattoos containing PPD has been associated with an increase in reported allergic skin reactions [1]. Reports indicate that the concentration of PPD in henna tattoos is alarmingly high, often exceeding regulated levels [3], further elevating the risk of allergic reactions.

H.S.K. drafted the manuscript, and M.L.G. critically revised it. Both authors reviewed and approved the final manuscript and gave consent for publication.

The authors have nothing to report. The patient in this manuscript has provided written informed consent for the use of her deidentified anonymized data and her case details (including photographs) for publication. Ethical Approval: not applicable.

The authors declare no conflicts of interest.