Abstract:

Objective To investigate the influences of routine-dose loratadine on the positive patch test reaction to nickel sulfate. Methods A double-blind, controlled and randomized study was carried out. A total of 121 patients with a positive patch test reaction to nickel sulfate were divided into two groups to receive loratadine 10 mg （experimental group, n = 61） or placebo （control group, n = 60） once daily for 14 days. The patch testing of nickel sulfate was performed on day 11, and clinical evaluation of the test was carried out on day 14 after the start of treatment. The intention to treat population was used for data analysis. Results No changes were observed in the intensity of patch test reaction to nickel sulfate in 55 patients in the experimental group or 53 patients in the control group, and there was no significant difference between the two groups in the percentage of patients showing changes in the intensity of patch test reaction （9.8% vs. 11.7%, χ2 = 0.11, P > 0.05）. Conclusion The routine-dose loratadine has no inhibitory effect on the intensity of skin patch test reaction to nickel sulfate.

Key words: inhibitory effect