The Scandinavian standard photopatch test procedure.

Recognizing the growing need for international standardization of photopatch testing techniques, a standard procedure has been used by Scandinavian dermatological clinics since January 1980. The set-up includes a standardized patient examination scheme, including phototest evaluation of the patient's UVA- and UVB-sensitivity, a standard photopatch tray containing 19 substances, and uniform techniques and criteria for the application and evaluation of the tests. Although modifications may be necessary in the future, preliminary experience with the Scandinavian photopatch set-up has been encouraging, and several positive reactions to most of the substances used have been recorded in the first 350 patients tested.