Clinical reports: Antiinflammatory properties of cetirizine in a human contact dermatitis model: Clinical evaluation of patch tests is not hampered by antihistamines
Jean Jacques Grob, Michel Castelain, Marie Aleth Richard, Jean Pierre Bonniol, Valérie Beéraud, Hertzel Adhoute, Nadia Guillou, Jean Jacques Bonerandi
The aim of this double-blind, placebo-controlled, randomized, cross-over pilot study was to assess the antiinflammatory properties of cetirizine. 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-day period, respectively. At day 11 of each period, patch testing was performed with the allergen. The image analysis showed a skin reaction significantly reduced under cetirizine (p = 0.03), but the clinical recording and the standardized chromatometry did not show any difference between groups. In the cross-over analysis the results of image analysis were influenced by the period, but this effect disappeared after adjustment of the ambient temperature during the 3 days of the test. These results demonstrate that cetirizine has an impact on the inflammatory process in a clinical model of cell-mediated allergic reaction, although this effect is only detected with a very sensitive technique. They also show that it is useless to stop antihistamines before patch testing, since clinical evaluation of tests is not hampered by a potent antihistamine. Additionally this study suggests that ambient temperature has an influence on the results of tests.