Schwarze Hennatattoos: eine unterschätzte Ursache für Lawson- und Benzocainallergie

Abstract

Background and aims: Paraphenylenediamine (PPD) was identified as the major allergen responsible for most contact reactions due to black henna tattoos. Lawsone, a naphthoquinone (2-hydroxy-1,4-naphtoquinon) and the allergenic compound in henna, seemed to have low sensitization potential. As a consequence, lawsone was not considered important in adverse reactions to henna tattoos. Methods: 12 Patients with adverse reactions to black henna tattoos were investigated. Epicutaneous tests were performed using a standard series. Furthermore, PPD at a concentration of 1% and lawsone at a concentration of 10% were used. The substances were applied to the upper back. Readings were made after 3 days. Reactions were scored as recommended by the ICDRG. Results: Patch test results revealed 11 allergic reactions to PPD 1%, 4 allergic reactions to lawsone 10%, 4 to benzocaine 5% and 2 to IPPD 0,1%. Conclusion: All patients with allergic reactions after black henna tattoos reacted as expected to PPD, but 4 of 11 also to lawsone. In this context, lawsone might have more relevance than previously assumed. Furthermore, 4 of 11 patients showed cross-sensitization to benzocaine which, in this circumstance, might be attributed more clinical value as well. Taken these observations and the rare occurrence of contact allergic reactions due to lawsone into consideration, it seems that the allergic reaction caused by the potent allergen PPD triggers sensitization to weak allergens.