CD12 Severe allergic contact dermatitis to jagua henna temporary tattoo

Abstract para-Phenylenediamine (PPD) in black henna tattoos is a well-known sensitizing agent causing allergic contact dermatitis; however, the safety of other products used in temporary tattoos is limited. Jagua and jagua henna temporary tattoos are becoming increasingly popular, owing to claims of these being natural, safe and free from PPD. Jagua temporary tattoo is made from genipin, an extract from the sap of the unripe fruit of Amazonian tropical Genipa americana or South East Asian Gardenia jasminoides. Extracts of G. americana fruits have been used by indigenous Amazonian people for its dyeing properties and also in traditional Chinese medicine for centuries. On the skin, genipin binds to epidermal proteins to form dark blue or black pigment that can last up to 10 days (Wilmot MC, Wakelin SH. Allergic contact dermatitis caused by jagua temporary tattoo. Clin Exp Dermatol 2020; 45: 261–2). It can be used alone in jagua temporary tattoos or mixed with henna paste. Genipin is also currently used for its crosslinking effect in the manufacture of polysaccharides, and is being investigated for its anti-inflammatory properties. We present the case of a 29-year-old female patient seen in the cutaneous allergy clinic for a severe painful blistering rash that developed 2 days after application of jagua henna on her hands and forearms. The rash worsened over several days with significant oedema, erythema and vesiculations. She had performed a localized test patch 28 days prior to jagua henna application, which did not show any reaction. She had used natural henna and dyed her hair on previous occasions with no reactions. She required treatment with a 7-day course of oral steroid, flucloxacillin and fexofenadine as it was not responding to topical steroid creams. Patch testing was performed to the British baseline series, and also to cosmetics, fragrances and hairdresser series. Her own products were applied, which included jagua henna and eucalyptus henna. The patch test result came back entirely negative to PPD and toluene-2,5-diamine at day 2 and 4; however, there was a strong positive reaction to jagua henna and a weak positive reaction to eucalyptus henna. The patch tests also showed positive reactions to balsam of Peru, fragrance mix I, hydroperoxide of linalool, and 2-n-octylisothiazolinone. We report a case of allergic contact dermatitis caused by jagua henna temporary tattoo, which highlights the presence of an emerging allergenic substance ‘genipin’ used in temporary tattoos.