The effect of montelukast (10mg daily) and loratadine (10mg daily) on wheal, flare and itching reactions in skin prick tests.

UNLABELLED: Antileukotriene agents are widely used for the treatment of allergic conditions including bronchial asthma and allergic rhinitis. The influence of montelukast on skin reactivity has not been clearly evaluated. The aim of this study was to determine the effect of montelukast on wheal, flare and itching in skin prick tests (SPTs).

METHODS

Fifteen atopic patients (5 women and 10 men) with average age 28.04 (SD+/-8.24) were tested with histamine, codeine, negative control solution and allergen extract (grasses). Montelukast (10mg), loratadine (10mg) or placebo were given to the volunteers for 5 days in a double-blind manner, followed by SPT, with 14 days of wash-out period.

RESULTS

There was no differences in wheal, flare and itching (p=0.205; 0.086 and 0.069, respectively, Wilcoxon rank-sum test) between SPT performed after placebo and wash-out period. The analysis revealed a statistically significant suppression of wheal and flare by loratadine (p<0.05 for all tested solutions). Pre-treatment with montelukast did not influence wheal size (p=0.099, 0.21, 0.066 for histamine, codeine and allergens, respectively), but significantly reduced flare (p=0.005; 0.003; 0.02 for histamine, codeine and allergens, respectively). We found a significant suppression of itching produced by montelukast (p=0.02) and loratadine (p=0.03) as compared to placebo (p=0.068 vs. wash out).

CONCLUSIONS

Our data show a tendency to suppressive effect of montelukast on flare and itching but not on wheal which is basic for SPT interpretation. We conclude that found suppression have little impact on clinical effectiveness of SPT as a diagnostic tool.