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.
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.