Para-phenylenediamine and its multiple co-sensitisations – two case reports

Abstract

Introduction. In contact allergology, the situations with simultaneous positive tests to multiple molecules are not rare; sometimes, in these cases, interpretation and clinical relevance of the tests are difficult. Case report I. A 73-year-old woman, with chronic blepharoconjunctivitis and chronic rhinitis (under observation), not responding to the treatment with tobramycin ophthalmic drops, olopatadine ophthalmic drops, dexamethasone phosphate injectable solution, mometazone furoate nasal spray and fluorometholone ophthalmic drops. Personal history: ten years ago - dermatitis on the face and scalp after using black dye hair. Epicutaneous tests: European Baseline Series + additional series, three components of cortico­steroid series. Results: +++ to para-phenylenediamine (PFD), ++ to neomycin, Peru balsam, budesonide, tixocortol-21-pivalate, benzalkonium chloride, textile dye mix, disperse orange. Case report II. A 50-year-old woman, without personal history of atopy, presented three months ago an acute eczema on the scalp and neck after using black dye hair. Under treatment with strong corticosteroids, the evolution was favorable, the eczema being at the time of testing in the chronic stage (lichenification). Epicutaneous tests: European Baseline Series + additional series. Results: ++ to PFD and nickel, + to colophane, Peru Balsam, Paladium, Orange Disperse 1, textile dye mix. Clinical relevance of the tests. In both cases primary sensitization was caused by hair dye, the responsible hapten being para-phenylenediamine; the positive results to textile dye mix and disperse orange 3 in the first case, respectively, to textile dye mix and disperse orange 1, in the second case, are justified by the cross-reactions they may have with PFD. The positivity of the tests to budesonide and tixocortol pivalate but also to benzalkonium chloride, in the first case, can be explained by sensitization via fluorometolone, respectively, by the presence of benzalkonium chloride as an excipient in dexamethasone phosphate injectable solution,tobramycin ophthalmic drops, olopatadine ophthalmic drops and fluorometholone ophthalmic drops. Conclusion. Our results are concordant with those recently published, which showed that PFD is one of the top-ranking allergens regarding the absolute number of significant associations with concomitantly patch tested allergens, suggesting the possibility to identify a subset of patients who are genetically prone to multiple sensitizations.