Diagnosis of Allergic Rhinitis
Prick skin testing is the diagnostic test of choice for identifying allergens. The test is safe, specific, and rapid.
Diagnosis of allergic rhinitis is based on symptoms and exposure history. Affected patients generally give a positive family history of Allergic Rhinitis (AR). It is thus a complex genetic disorder. Detailed physical examination by your doctor may reveal a nasal mucosa that is pale, cyanotic, and swollen with clear secretions. Nasal smears of secretions are rarely used for study.
Allergy testing may be used to identify the specific allergen that triggers AR. A number of tests are available for this purpose. The most common ones are:
- Skin tests
- Blood tests (including the radioallergosorbent, or RAST Test)
Prick skin testing is the diagnostic test of choice for identifying allergens. The skin is pricked with a small amount of suspected allergy-causing substances. Signs of reaction are watched for (swelling, redness). Results are usually seen within 15-20 minutes. The test is safe, specific, and rapid.
Intra-dermal testing is not routinely employed since it is rarely associated with potentially life-threatening systemic reactions.
Specific blood tests (IgE immunoassays) measure the levels of specific allergy-related substances such as Immunoglobulin E (IgE) levels. Complete blood count (CBC) is also done to reveal allergies (eosinophil white blood cell count is high in allergies).
- Cecil Medicine, 23rd Ed.
- The Merck Manual, 18th Ed.