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.
Steroid nasal sprays rarely cause side-effects. This is because they are applied directly to the nose and very little of this medicine is absorbed into the body. Therefore, they are much less likely to cause side-effects in other parts of the body. Occasionally, they cause dryness, crusting, and bleeding of the nose. If this occurs, stop it for a few days and then restart. There have been reports of nasal steroids possibly having an effect on behaviour, particularly in children. This is thought to be rare. However, a few people have reported hyperactivity, problems sleeping, anxiety, depression, and aggression.