PATCH TESTING WITH THE SESQUITERPENE LACTONE MIX - A MARKER FOR CONTACT ALLERGY TO COMPOSITAE AND OTHER SESQUITERPENE-LACTONE-CONTAINING PLANTS

6278 patients were patch tested with a sesquiterpene lactone mix (SL‐mix) in 10 European clinics. 4011 patients were tested only with 0.1% SL‐mix. 63 (approximately 1.5%) of whom were positive, with 26 (41%) of these cases being considered clinically relevant. There were no cases of active sensitization occurred though 5 eases of irritation were reported. 22 irritant reactions and 22 cases of active sensitization occurred when testing also with 1% and 0.33% concentrations of SL‐mix. SL‐mix 0.1% pet is shown to be an important patch test and many relevant sensitizations will be missed without routine screening with such a mix. Most patients with SL‐mix sensitivity presented with hand and/or face dermatitis, apparent photodermatitis or more generalised eczema. Copyright © 1990, Wiley Blackwell. All rights reserved