ANTIINFLAMMATORY PROPERTIES OF CETIRIZINE IN A HUMAN CONTACT-DERMATITIS MODEL - CLINICAL-EVALUATION OF PATCH TESTS IS NOT HAMPERED BY ANTIHISTAMINES

The aim of this double-blind, placebo-controlled, randomized, cross-ov er pilot study was to assess the antiinflammatory properties of cetiri zine. A group of 27 patients with a positive patch test to an allergen consecutively received cetirizine 10 mg o.d. or placebo during a 14-d ay period, respectively, At day 11 of each period, patch testing was p erformed with the allergen. The image analysis showed a skin reaction significantly reduced under cetirizine (p=0.03), but the clinical reco rding and the standardized chromatometry did not show any difference b etween groups, In the cross-over analysis the results of image analysi s were influenced by the period, but this effect disappeared after adj ustment of the ambient temperature during the 3 days of the test. Thes e results demonstrate that cetirizine has an impact on the inflammator y process in a clinical model of cell-mediated allergic reaction, alth ough this effect is only detected with a very sensitive technique, The y also show that it is useless to stop antihistamines before patch tes ting, since clinical evaluation of tests is not hampered by a potent a ntihistamine. Additionally this study suggests that ambient temperatur e has an influence on the results of tests.