Abstract
This study is of the effect of the blockade of histamine H 1 receptors by a long-acting antihistamine on the immediate and late clinical response to antigen (Ag) and on the recruitment of eosinophils in the late-phase cutaneous reaction. Ten adult volunteers with late-phase reactions to the intradermal injection of either Dermatophagoides pteronyssinus or Phleum pratense (timothy) pollen performed a double-blind, crossover study. Each volunteer took astemizole, 10 mg, or identical placebo, daily for 2 weeks. Ag in the concentration that induced a late reaction in the screening visit was injected intradermally at the end of each drug period. The early reaction was measured serially for 30 minutes and the late reaction at 4 and 6 hours. Biopsies of the Ag and control sites were also performed at 6 hours. After a 6-week washout period, subjects then took the opposite medication for 2 weeks and returned for skin testing and biopsy. Skin testing demonstrated that astemizole inhibited the immediate response to both histamine and allergen but had no effect on the late response at 4 hours and at 6 hours. Biopsy specimens revealed no significant effect on eosinophil recruitment at 6 hours. We conclude that histamine H 1-receptor blockade has no effect on the late cutaneous reaction to Ag.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.