If symptoms are severe or unusually persistent, your doctor should probably test you to find out exactly what’s causing the trouble. The real culprit might not be ragweed at all, but another environmental allergen or even certain foods, such as chamomile and banana.
Two allergy tests are widely used:
- A blood test checks for the presence of antibodies to ragweed. It’s reliably accurate, but takes up to two weeks to get results.
- A skin-prick test is fast, but can yield a false negative result if you are taking an antihistamine. Minute quantities of various substances are injected into the skin. If a wheal forms that’s larger than the control substance, the test skin prick is considered positive.
The ultimate weapon against ragweed allergy (and allergies in general) is immunotherapy. In this tried-and-true therapy — effective in about 85% of allergic rhinitis sufferers — the patient receives a series of injections of the allergy-causing agent until the body no longer mounts an immune response. The injections are typically given for several months before determining responsiveness to treatments
In recent years, American doctors — following the lead of their counterparts in Europe — have begun treating ragweed allergy sufferers with sublingual immunotherapy instead of allergy shots. Drops of liquid are placed under the tongue. Sublingual immunotherapy can be more convenient than traditional immunotherapy — no need to come in for shots — and it takes less time. Results are often seen within weeks or months.