If springtime gardening is always followed with a runny nose or if you constantly sneeze while visiting that friend with the cute pet, you are not alone. According to the American Academy of Allergy, Asthma, and Immunology (AAAAI), 54.6 percent of the American population have been found to be susceptible to at least one allergen. To diagnose and treat the condition, an allergy and immunology specialist will perform an allergy skin test. An allergy skin test is a procedure in which allergens are applied in small amounts under the skin. To ensure allergy test results are not skewed, you should avoid certain medications.
Antihistamines
Antihistamines can either be prescribed or found over the counter. Medications such as loratadine (Claritin) and diphenhydramine (Benadryl) are classified as antihistamines because they act as a determent to histamine actions in the body, which prevents allergy symptoms. The primary goal of allergy testing is to induce an allergic response, which will pinpoint exactly what you are allergic to. Because of this, refrain from using antihistamines for a minimum of 48 to 72 hours beforehand.
Tricyclic Antidepressants
Tricyclic antidepressant (TCA) medications, such as doxepin (Aponal) and amitriptyline (Elavil), also interfere with skin allergy testing results. It was discovered by the American College of Allergy, Asthma, and Immunology (ACAAI) that more than half of the patients taking TCAs did not respond to allergy testing. These medications should not be taken at a minimum of 48 to 72 hours before testing. Always check with your provider before stopping any medication.
H2 Blockers
H2 blockers are used to treat acid reflux. Medications such as ranitidine (Zantac) and famotidine (Pepcid) fall into this category. H2 blockers alters histamine activity in the body, but it acts differently from the antihistamines used to treat allergy symptoms. H2 blockers affect the histamine receptors in the stomach as opposed to the nose and skin. Although not found to cause significant allergy testing interference by the ACAAI, it's still standard practice to avoid these medications for a minimum of 48 to 72 hours before skin testing.
References
- American Academy of Allergy, Asthma, and Immunology (AAAAI): Allergy Statistics
- American College of Allergy, Asthma & Immunology (ACAAI) 2009 Annual Scientific Meeting: Abstract 23. Presented Nov. 8, 2009
