OLAQUINDOX-INDUCED AIRBORNE PHOTOALLERGIC CONTACT-DERMATITIS FOLLOWEDBY TRANSIENT OR PERSISTENT LIGHT REACTIONS IN 15 PIG BREEDERS

There have been no previous reports of photosensitivity following phot oallergy to airborne olaquindox in a large group. 15 pig breeders, wit h photo-distributed dermatitis related to olaquindox dust, were invest igated to study the nature, promoting factors, and course of this dise ase. Minimal erythema doses for WA and UVB were established before pho topatch testing and at intervals thereafter. All patients presented wi th olaquindox-induced photoallergy. Ln 14 cases, this was followed by prolonged increased sensitivity to UVA. 7 patients also displayed an i ncreased sensitivity to UVB. 13 farmers came into contact with olaquin dox in mineral feed (1000 mg/kg) and only 2 in final feed (50 mg/kg). 8 patients avoided further contact with olaquindox because of warnings in the media. Allergies and photoallergies to other occupational subs tances preceded or followed olaquindox (photo)allergy. Because of thei r increased sensitivity to light, most of these farmers used sunscreen s, and 2 of them developed (photo)allergy to UV-absorbers. As a result of our studies, we recommend photopatch testing for olaquindox in pig breeders with photo-distributed dermatitis. This would enable the ear ly recognition of photoallergy to olaquindox and the prevention of per sistent light reaction.