Categorization of fragrance contact allergens for prioritization of preventive measures: clinical and experimental data and consideration of structure–activity relationships

Contact allergy to fragrances is still relatively common, affecting ∼ 16% of patients patch tested for suspected allergic contact dermatitis, considering all current screening allergens. The objective of the review is to systematically retrieve, evaluate and classify evidence on contact allergy to fragrances, in order to arrive at recommendations for targeting of primary and secondary prevention. Besides published evidence on contact allergy in humans, animal data (local lymph node assay), annual use volumes and structure-activity relationships (SARs) were considered for an algorithmic categorization of substances as contact allergens. A total of 54 individual chemicals and 28 natural extracts (essential oils) can be categorized as established contact allergens in humans, including all 26 substances previously identified as contact allergens (SCCNFP/0017/98). Twelve…