P59 Patch test results to plant extracts and chemicals

Objective and methods:  We review patch test results from two special patch test series for plant allergens, ‘plant extracts’ and ‘allergenic plant chemicals’, provided by Prof. Hausen (Germany) and tested in 1992–2003. The standard series contained Sesquiterpene-lactone mix (SL mix) since 1993 (3/1998–10/1999 excluded) and Compositae mix since 3/1998. We present the cases where either SL mix or Compositae mix gave an allergic reaction and where, in addition, the series of plant extracts was tested. Results:  SL mix and Compositae mix were tested to 900 patients. Among them, plant extracts were tested in 122 and plant chemicals in 104 cases. 30 patients had an allergic reaction to Compositae mix and 17 to SL mix as well. In the plant extract series, there were more than 5 allergic reactions to feverfew(21), true chamomile(21), arnica(18), chrysanthemum(18), laurel bay leaf(13), tansy(12), gaillardia(9), yarrow(8) and pot marigold(7). In the plant chemical series, there were 9 allergic reactions to parthenolide and single reactions to primin, chlorophorin and Mansonone A. Conclusions:  Compositae mix gave a positive test reaction always together with SL mix, which gave a positive reaction in only part of these cases. The concentration of Compositae mix was lowered from 6% to 3% in 1/1999 because of cases of active sensitisation. The lower concentration seems to be reliable for detecting allergy, although it still causes active sensitisation.