CELLULAR INFLAMMATORY RESPONSES AND MEDIATOR RELEASE DURING EARLY DEVELOPING LATE-PHASE ALLERGIC CUTANEOUS INFLAMMATORY RESPONSES - EFFECTSOF CETIRIZINE

Background: Events in developing cutaneous late-phase allergic reactio ns can be characterized by a combination of skin chamber and biopsy ap proaches. In some previous studies, cetirizine reportedly inhibited me diator release and/or inflammatory cell responses in late-phase reacti ons. Objective: This study was carried out to determine the effects of cetirizine on early late-phase reactions by using skin chamber and sk in biopsy specimens. Methods: Skin chamber responses during a 6-hour c hallenge with pollen antigens were assessed in 15 sensitive subjects d uring randomized, crossover treatment with cetirizine (20 mg/day) or p lacebo for 7-day periods with measurements of humoral and cellular com ponents. Biopsy specimens of the underlying dermis sere obtained. Resu lts: During cetirizine treatment, there was significant (p < 0.01) inh ibition of immediate wheal and flare reactions to pollen antigens (34, 46%), codeine (41, 65%), and histamine (35, 68%). However, gross late -phase reactions at 6 hours mere unaffected. During both cetirizine an d placebo treatment, there was significantly greater accumulation at a ntigen sites in: (1) skin chamber levels of histamine, total cells, la ctoferrin, and eosinophil cationic protein; (2) eosinophils (total and activated) on appended cover glasses; (3) deposition of lactoferrin a nd eosinophil cationic protein in the underlying dermis. However, thes e responses were not significantly differed during cetirizine treatmen t compared with placebo treatment periods. Conclusion: A persistent pa ttern of inflammatory cell accumulation with release of granule protei ns during early late-phase reactions was unaffected by cetirizine trea tment.