Most people tolerate allergy shots well, but there are some common side effects a person might experience. Among the most common side effects of allergy shots are redness and swelling at the injection site as well as discomfort or bruising in the area. Some people may also experience non-localized side effects such as coughing and sneezing. Wheezing and itchy eyes may also develop after a person has received an allergy shot. Much more rarely, an individual might suffer a severe and life-threatening allergic response as one of the side effects of allergy shots.
One of the most common side effects of allergy shots is irritation that develops at the site of the injection. This occurs because the substance that the person is allergic to enters the body at this point and can cause an allergic reaction at the injection site. Some of the types of reactions a person may experience at the injection site include reddening of the skin, swelling, and itching. Some people may also develop a minor rash or bump in the area. Interestingly, many people develop such irritation just a few minutes after they receive an allergy shot while others do not notice a reaction until at least a few hours later.
Discomfort at the time of the injection may also be considered a side effect of an allergy shot. This type of side effect is usually only minor, however, as most people feel only a small pinch, sting, or burn when they have these types of injections. These shots, however, generally produce far less discomfort than other types of shots do, and medical professionals often try to numb the area so they will not hurt. For example, a nurse may gently pinch the area to create a numbing effect or apply a topical anesthetic to the skin.
Some people may also experience bruising at the injection site in response to an allergy injection. A person may develop an occasional bruise after having an allergy shot or he may bruise every time. Usually, however, the bruising only lasts for a very short period of time.
Other common side effects of allergy shots include non-local allergic reactions. For example, an individual may experience whatever allergic reaction he would normally have in response to the allergen. He might cough or sneeze, for example, or experience itchy eyes and throat. Some people may also have wheezing or chest tightness as well. It is important to note, however, that such side effects are more likely to occur when a person does not adhere to his normal schedule of injections.
Rarely, a person will develop an allergic reaction called anaphylaxis in response to having an allergy shot. This is a life-threatening allergic reaction that is often accompanied by tightness in the chest and difficulty breathing. A person may also lose consciousness in such a case. An individual who develops this reaction needs immediate medical attention.