Your doctor may be able to diagnose hay fever based on your medical history, a physical exam, and your symptoms. Skin tests may be recommended to determine which substances trigger your allergies.
In a skin test, the doctor applies drops containing a small amount of allergy-causing substances called allergens to your arm or back. The procedure is painless and draws no blood. Developing a red, itchy bump in 15-20 minutes strongly suggests an allergy to that substance.
Some doctors use intradermal testing, where a small drop of the substance is placed under the skin with a needle and evaluated in 15-20 minutes.
A blood test may be used to check your blood for elevated levels of antibodies produced by your immune system against certain allergens. Each test has advantages and disadvantages.
What Are the Treatments for Hay Fever?
For hay fever, the best approach is to avoid allergens and other triggers (such as smoke and dust).
Mild cases of hay fever can usually be controlled with an over-the-counter (OTC) non-sedating antihistamine, such as cetirizine (Zyrtec), desloratadine (Clarinex), fexofenadine (Allegra), or loratadine (Alavert, Claritin). Older OTC antihistamines, such as chlorpheniramine and diphenhydramine, can cause drowsiness. This drowsiness can increase the risk of accidents when driving or operating other vehicles or tools.
Antihistamines are much more effective when taken daily during your allergy season rather than only on days when you have symptoms.
Phenylephrine and pseudoephedrine are decongestants that help unblock nasal passages and are also in many over-the-counter products. If you're taking medication for a heart condition, the antibiotic erythromycin, or the antifungal drug ketoconazole, be sure to check with your doctor before taking a decongestant or antihistamine to avoid drug interactions. For severe cases, your doctor may also suggest OTC fexofenadine or prescribe desloratadine, which is typically more effective with fewer side effects than loratadine for some patients with hay fever.
The FDA has approved the prescription antihistamine nasal sprays azelastine (Astelin, Astepro) and olopatadine (Patanase) to relieve the symptoms of seasonal allergic rhinitis. These may be used in patients age 5 and older.