We report a case of a severe allergic reaction following hair dye application in a 60-year-old woman with a history of liver transplantation in 2003, maintained on tacrolimus 3.5 mg. The patient was known for multiple allergies, including peanut, oral allergy syndrome, and anaphylaxis to vancomycin and influenza vaccination. Ten minutes after the application of a black-coloured hair dye (Syoss Permanent, Henkel AG a negative response therefore points to decreased mast-cell density and/or impaired degranulation capacity, which may contribute to the difference between skin and in vitro testing. Tacrolimus is a known suppressor of mast cell activation and histamine release acting probably via the MRGPRX2 receptor 8, 9. Therefore, we were not astonished to see the difference between a positive histamine reaction on the skin induced by exogenous histamine and a lack of response to codeine as well as the suspected culprits due to a lack of mast cell activation by tacrolimus. Additionally, petrolatum-based preparations, while standard for patch testing, may not be optimal vehicles for prick testing with these compounds. BAT, by directly assessing basophil reactivity ex vivo, bypasses these cutaneous confounders and may therefore offer greater sensitivity in this clinical context. To the best of our knowledge, this is the first documented case of IgE (or IgG)-mediated hair dye anaphylaxis with positive results in both BAT and LTT. Potential cross-reacting hair dyes should be included in the testing to increase patient safety. Written informed consent was obtained from the patient for the publication of this manuscript, including any accompanying clinical information and images. Pierre Piletta: writing – review and editing. Eglė Janušonytė: conceptualization, investigation, writing – original draft. Sophie Vandenberghe-Dürr: writing – review and editing, conceptualization, investigation. Thomas Harr: writing – review and editing. Open access publishing facilitated by Universite de Geneve, as part of the Wiley - Universite de Geneve agreement via the Consortium Of Swiss Academic Libraries. The authors have nothing to report. The authors declare no conflicts of interest. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
Janušonytė et al. (Wed,) studied this question.