CONTACT AND PHOTOCONTACT SENSITIVITY TO SUNSCREENS - REVIEW OF A 15-YEAR EXPERIENCE AND OF THE LITERATURE

This review summarizes published and unpublished data of our 15-year e xperience with sunscreen allergy and photoallergy. From 1981-1996, 402 patients with suspected clinical photosensitivity were patch and phot opatch tested with the commercial sunscreens and facial cosmetics that they had used and with chemical UV absorbers, fragrance materials, pr eservatives, and emollients. 80 patients (20%) (28 men, 52 women) demo nstrated allergic and/or photoallergic contact dermatitis to 1 or more UV absorber(s). In 47 patients with photodermatoses or photo-aggravat ed dermatoses and in 33 subjects with normal photosensitivity, 91 alle rgic and 84 photoallergic reactions to UV filters were observed. Over the years sunscreens were added to the test series, which since 1989 c omprised the following 10 UV absorbers and which induced allergic (a) and photoallergic (pa) reactions (number, type of reaction): 4 UVA abs orbers - isopropyldibenzoylmethane (30a/32pa); butyl methoxydibenzoyl- methane (15a/13pa); benzophenone-3 (3a/9pa); benzophenone-4 (0a/0pa); and 6 UVB absorbers - PABA (2a/2pa); octyl dimethyl PABA (1a/2pa); met hylbenzylidene camphor (32a/5pa); octyl methoxycinnamate (3a/4pa); iso amyl p-methoxycinnamate (4a/10pa); and phenylbenzimidazole sulfonic ac id (1a/7pa). The frequent (photo)sensitization to isopropyldibenzoylme thane was the reason that its production was discontinued in 1993. 47 patients reacted to fragrance materials, 11 to preservatives and 2 to lanolin alcohol. These constituents were contained in the commercial s unscreens and cosmetics that they had used. Continuous revision of the UV absorber photopatch test series was necessary to be closer to the real frequency of exposure and of reported (photo)allergy to newer sun screens. Clinicians should consider contact and photocontact allergy, especially in patients with photodermatoses and photo-aggravated derma toses, and they should perform photopatch testing. Once the culprit ha s been identified, its INCI (International Nomenclature Cosmetic Ingre dients) designation should be given to the patient, who must be warned to avoid products containing the (photo)allergen.