Contact and photocontact allergy to oxybenzone.

The purpose of this study was to determine the frequency of contact allergy and photocontact allergy to sunscreens. A consecutive series of 54 patients with suspected clinical photosensitivity were assessed. All had the same standardized photobiological investigation from January 1989 to December 1990, including patch tests and photopatch tests with 6 sunscreen agents. Oxybenzone was found to cause 4 cases of allergic contact dermatitis (with photoaggravation in 2), and 3 cases of photocontact dermatitis (13% of patients). This is probably due to the wide distribution of oxybenzone in sunscreens and other cosmetics, 2 patients with polymorphic light eruption and persistent light reactivity, respectively, were regular sunscreen users. Photobiological investigation is necessary to ensure accurate diagnosis, since sunscreen contact or photocontact allergy may simulate other photosensitivity eruptions.     

Contact and photocontact sensitivity to sunscreens

This review summarizes published and unpublished data of our 15-year experience with sunscreen allergy and photoallergy. From 1981–1996. 402 patients with suspected clinical photosensitivity were patch and photopatch tested with the commercial sunscreens and facial cosmetics (hat they had used and with chemical UV absorbers, fragrance materials, preservatives, and emollients. Mi patients (20%) (28 men, 52 women) demonstrated allergic and/or photoallergic contact dermatitis to 1 or more UV absorber(s). In 47 patients with photodermatoses or photo-aggravated dermatoses and in 33 subjects with normal photosensitivity, 91 allergic and 84 photoallergic reactions to UV filters were observed. Over the years sunscreens were added lo the test series, which since 1989 comprised the following 10 UV absorbers and which induced allergic (a) and photoallergic (pa) reactions (number, type of reaction); 4 UVA absorbers – isopropyldibenzoylmethane (30a/32pa); butyl methoxydibenzoyl-methane (15a/13pa); henzophenone-3 (3a/9pa): benzophenone-4 (0a/0pa); and 6 UVB absorbers – PABA (2a/2pa); octyl dimethyl PABA (1a/2pa); methylbenzylidene camphor (32a/5pa); octyl methoxycinnamate (3a/4pa); isoamyl p-methoxycinnamate (4a/10pa); and phenylbenzimidazole sulfonic acid (1a/7pa). The frequent (photo)sensitization to isopropyldibenzoylmethane 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 sunscreens 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 I photo (allergy to newer sunscreens. Clinicians should consider contact and photocontact allergy, especially in patients with photodermatoses and photo-aggravated dermatoses and they should perform photopatch testing. Once the culprit has been identified, its INCI (International Nomenclature Cosmetic Ingredients) designation should be given to the patient, who must be warned to avoid products containing the (photo)allergen.     

Evaluation of customers'' complaints about sunscreen cosmetics sold by the Swedish pharmaceutical company

Sweden's pharmacies hold more than a 1/3 of the country's market for sunscreen cosmetics (sunscreens). Customers complaining of skin problems associated with the use of sunscreens obtained from the pharmacies were offered dermatological investigation and tests with standard allergens and sunscreens. 27 of 58 complaining customers were fully investigated, and another 8 partly tested. 2 disease entities, a burning sensation and erythema for one or a few days, and dermatitis with scaling lasting for up to 3 weeks, were about equally common. Contact or photocontact allergy to 2-hydroxy-4-methoxybenzophenone caused severe contact dermatitis in 3 individuals.     

Contact allergy to sunscreen chemicals in photosensitivity dermatitis/actinic reticuloid syndrome (PD/AR) and polymorphic light eruption (PLE)

From 1989-1991. 214 patients (45 PD/AR, 54 PLE, 115 controls) were patch tested to a sunscreen series containing 9 constituents. 16/214 (7.5%) patients reacted in one or more sunscreens, with allergy being significantly more common in PD/AR patients (10–45 versus 2/54 PLE and 4/115 contact dermatitis clinic controls). The benzophenone group of sunscreens (mexenone, oxybenzone) were the most frequent sensitizers, accounting for 8 of the 27 positive patch tests observed. Clinicians should consider contact allergy to sunscreens in PD/AR patients as an explanation for exposed-site dermatitis episodes.     

Contact and photocontact allergy to ketoprofen: clinical and experimental study

In the last 3 years, we have studied 10 patients with allergic reactions to topical ketoprofen. We have investigated the sensitization and irritant potential of the drug and the possibility of cross-reactivity with other aryl-propionic non-steroidal anti-inflammatory drugs (ibuproxam, ibuprofen, naproxen, fenoprofen, flubiprofen and tiaprofenic acid). 2 of our patients had contact dermatitis, and the other 8 photocontact dermatitis. One of our patients showed cross-reactivity between ketoprofen and ibuproxam on patch testing. In the photopatch tests, we observed cross-reactivity between ketoprofen and tiaprofenic acid in 2 patients, and cross-reaction between ketoprofen and ibuproxam and flurbiprofen in another case. Experimental studies, including human maximization and photomaximization tests, performed in 20 healthy volunteers, showed a complete absence of sensitization, 3 volunteers showed a marked irritant reaction to ketoprofen (20% pet.) during either maximization (2 cases) or photomaximization (1 case) tests. Although ketoprofen appears not to be a sensitizing agent in human volunteers, the fact that photosensitization to this drug seems to be quite common after topical use suggests that there are some local or individual factors, at present unknown, facilitating the development of allergy.     

Intravenous challenge with heparins in patients with delayed-type skin reactions after subcutaneous administration of the drug

Many contact allergens can cause an erythema-multifor-me (EM)-like or urticarial papular and plaque eruption (UPPE) (1–6). Although numerous topical medicaments have been reported as causing UPPE, oxybenzone (2-hydroxy-4-methoxy benzophenone, benzophenone 3, Eusolex 4360) has not.     

Contact allergy to tioconazole

In 15 months, we detected allergic patch lest reactions to tioconazole in 14 patients. 9 of the 14 patients were allergic to additional imidazole derivatives used as antifungal agems. The positive patch test rreactions to tioconazole may have been caused either by simultaneous sensitization or more probably by cross-reactivity between the various commercially used imidazole derivatives with a similar chemical structure. The abundant use of tioconazole in concentrated (up to 28%) topical formulations in Finland could be the major cause of the apparent increase in allergic reactions.