Fragrances are an important cause of allergic contact dermatitis. We presume that the traditional fragrance mix (FM) detects 70 to 80% of fragrance-allergic patients. FM has an irritant potential. Weak positive reactions may have a greater chance of being irrelevant than strong reactions.
To improve the appraisal of FM patch-test reactions, we studied the relevance of reactions of different strength. We also studied the predictive value of the following on the relevance of the initial FM patch-test results: patch-test results of a repeated FM test; results of patch tests with balsam of Peru, colophony, and ingredients of the mix; and (history of) atopic dermatitis.
One hundred thirty-eight patients who had doubtful positive (?+) or positive (+ to +++) reactions were included in the study. We determined relevance by history taking, location and course of the dermatitis, and additional patch testing. Patients were retested with FM and with each ingredient separately.
The relevance of reactions to FM increases with the strength of the reactions. Predictors of relevance are the results of retesting with FM, the results of tests with the ingredients, and a history and/or present symptoms of atopic dermatitis.
Retesting with FM and its ingredients may add to the benefit of patch testing.
From the Departments of Dermatology, Hospital H. Serruys, Ostend and Gent University Hospital, Gent, Belgium; the Department of Epidemiology and Biostatistics of the University Medical Centre St Radboud, Nijmegen, Netherlands; and the Departments of Dermatology of the following: St. Antonius Hospital, Nieuwegein, Netherlands; HagaZiekenhuis (Leyenburg), The Hague, Netherlands; Atrium Medisch Centrum, Heerlen, Netherlands; Free University Medical Center, Amsterdam, Netherlands; Groningen University Hospital, Groningen, Netherlands; Medisch Spectrum Twente, Enschede, Netherlands; Leiden University Medical Center, Leiden, Netherlands; Medical Center Haaglanden, Westeinde Hospital, The Hague, Netherlands; and University Medical Centre St Radboud, Nijmegen, Netherlands.
Address reprint requests to P.G.M. van der Valk, Department of Dermatology, Radboud University Nijmegen, P.O.Box 9101, NL-6500 HB, Nijmegen, The Netherlands. E-mail:P.vanderValk@derma.umcn.nl