It can be difficult to tell the difference between a cold and hay fever. If you have hay fever, your runny nose will likely have a thin, watery discharge, and, despite the name, you will not have a fever. If you have a cold, you may have a thicker or yellowish discharge from your nose, and may have a low-grade fever. Hay fever symptoms can begin immediately after you are exposed to allergens like pollen or animal dander , and will continue as long as your exposure continues. A cold will most likely begin a day or two after exposure to the virus, and can last a few days to a week.
Immunotherapy injections carry a small risk of a severe allergic reaction. These reactions occur with a frequency of 6 of every 10,000 injections. The symptoms usually begin within 30 minutes of the injection. For this reason, patients are required to remain in the office after routine injections so that such a reaction could be quickly treated. Because drugs called beta-blockers may interfere with the ability to treat these reactions, people who take beta-blockers are often advised to avoid immunotherapy. If patients are getting allergy shots and another clinician prescribes a beta-blocker medicine for high blood pressure or another reason, the patients must make sure to tell their allergy clinician.