In assessing a patient for allergic rhinitis, what is the most common diagnostic method?

The most common diagnostic method for allergic rhinitis is skin prick testing. This technique is widely used because it is effective, quick, and provides immediate results. During the skin prick test, small amounts of allergens are introduced into the skin's surface through tiny pricks. If the patient is allergic to a particular substance, they will develop localized redness and swelling, indicating a positive reaction.

Skin prick testing is favored due to its practicality in an outpatient setting and its ability to test multiple allergens simultaneously, which allows for a comprehensive assessment of the patient's sensitivities. It is also a cost-effective procedure with a high sensitivity and specificity for common allergens associated with allergic rhinitis, making it the preferred initial method of diagnosis.

Other diagnostic methods like blood serum testing can determine specific IgE levels, but these are typically used when skin testing is not possible, such as in patients with significant skin conditions or those who are taking medications that might interfere with skin testing. Nasal endoscopy is primarily used to evaluate structural abnormalities or chronic conditions rather than for diagnosing allergic rhinitis specifically. The histamine challenge test is used more in research settings and testing bronchial hyperreactivity rather than as a standard diagnostic tool for allergic rhinitis.