Montelukast Can Be Taken Before Skin Allergy Testing
Patients can continue taking montelukast (Singulair) before skin allergy testing as it does not significantly affect skin test results. 1, 2
Evidence on Montelukast and Skin Testing
Effect on Skin Test Results
- Multiple studies have demonstrated that montelukast does not suppress wheal reactions in skin prick tests:
- A double-blind placebo-controlled randomized trial showed that even after 21 days of montelukast treatment, there was no significant suppression of skin prick test responses to allergens 1
- Another prospective, randomized, double-blind study found no significant suppression of intradermal whealing after antigen challenge compared to placebo 2
- Unlike antihistamines (such as fexofenadine), which significantly suppress skin test reactions, montelukast showed no clinically relevant impact on skin test results 3
Clinical Implications
- There is no need to discontinue montelukast before performing skin allergy testing 1, 2
- This is in contrast to antihistamines, which should be discontinued before skin testing due to their suppressive effect on wheal and flare responses 1, 3
Mechanism of Action Explanation
- Montelukast works by blocking leukotriene receptors, specifically the cysteinyl leukotriene 1 (CysLT1) receptor 4
- This mechanism differs from antihistamines, which block histamine receptors directly involved in the wheal and flare response measured in skin testing
- The different mechanism explains why montelukast does not interfere with skin test results while antihistamines do
Important Considerations
Medication Washout Periods for Skin Testing
- While montelukast can be continued, other medications may need to be discontinued before skin testing:
- First-generation antihistamines: 3-7 days washout
- Second-generation antihistamines: 5-7 days washout
- Tricyclic antidepressants: 7-14 days washout
Potential Adverse Effects
- Though rare, be aware that montelukast can occasionally cause adverse skin reactions in some patients, including rash, urticaria, and angioedema 5
- These reactions are uncommon but should be monitored, especially within the first months of treatment
Summary
Montelukast does not need to be discontinued before skin allergy testing as it does not significantly affect skin test results. This allows patients to maintain their asthma or allergic rhinitis control while undergoing diagnostic skin testing.