Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis.Encyclopedia Entry for Allergy :Allergy shots. An allergy shot contains a small amount of an allergen. This is a substance that causes an allergic reaction. Examples of allergens include: Mold spores Dust mites Animal dander Pollen Insect venom A health care provider gives you the shots for 3 to 5 years. This series of allergy shots may help reduce your allergy symptoms. Work with your provider to identify which allergens are causing your symptoms. This is often done through allergy skin testing or blood tests. Only the allergens you are allergic to are in your allergy shots. Allergy shots are only one part of an allergy treatment plan. You may also take allergy medicines while having allergy shots. Your provider may recommend that you reduce your exposure to allergens, as well.Allergy symptoms occur when your immune system tries to attack an allergen in your body. When this happens, your body creates mucus. This can cause bothersome symptoms in the nose, eyes, and lungs. Treatment with allergy shots is also called immunotherapy. When a small amount of an allergen is injected into your body, your immune system makes a substance called an antibody that blocks the allergen from causing symptoms. After several months of shots, some or all of your symptoms may be relieved. Relief can last several years. For some people, allergy shots can prevent new allergies and reduce asthma symptoms.You may benefit from allergy shots if you have: Asthma that allergies make worse Allergic rhinitis, allergic conjunctivitis Insect bite sensitivity Eczema , a skin condition that a dust mite allergy can make worse Allergy shots are effective for common allergens such as: Weed and tree pollen Grass Mold or fungus Animal dander Dust mites Insect stings Adults (including the older people) as well as children 5 years and older can receive allergy shots. Your provider is not likely to recommend allergy shots for you if you: Have severe asthma. Have a heart condition. Take certain medicines, such as ACE inhibitors or beta-blockers. Are pregnant. Pregnant women should not begin allergy shots. But, they may be able to continue allergy shot treatment that was started before they became pregnant. Food allergies are not treated with allergy shots.You will get your allergy shots at your provider's office. They are usually given in the upper arm. The typical schedule is: For the first 3 to 6 months, you receive shots about 1 to 3 times a week. For the next 3 to 5 years, you receive the shots less often, about every 4 to 6 weeks. Keep in mind that many visits are needed to get the full effects of this treatment. Your provider will assess your symptoms now and then to help decide when you can stop receiving the shots.An allergy shot may cause a reaction on the skin, such as redness, swelling, and itching. Some people have mild nasal stuffiness or a runny nose. Though rare, an allergy shot can also cause a severe life-threatening allergic reaction called anaphylaxis. Because of this, you may need to stay in your provider's office for 30 minutes after your shot to check for this reaction. You may also need to take an antihistamine or another medicine before your allergy shot appointments. This may prevent reactions to the shot at the injection site, but it does not prevent anaphylaxis. Reactions to allergy shots can be treated in your provider's office right away.Call your provider if: You continue to have symptoms after several months of allergy shots You have questions or concerns about the allergy shots or your symptoms You have trouble keeping appointments for your allergy shots.Allergy injections; Allergen immunotherapy.Cox L, Nelson H, Lockey R, et al; Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. Allergen immunotherapy: a practice parameter third update. J Allergy Clin Immunol. 2011;127(1 Suppl):S1-S55. PMID: 21122901 www.ncbi.nlm.nih.gov/pubmed/21122901. Golden DBK. Insect allergy.Encyclopedia Entry for Allergy :Allergy testing - skin. There are three common methods of allergy skin testing. The skin prick test involves: Placing a small amount of substances that may be causing your symptoms on the skin, most often on the forearm, upper arm, or back. The skin is then pricked so the allergen goes under the skin's surface. The health care provider closely watches the skin for swelling and redness or other signs of a reaction. Results are usually seen within 15 to 20 minutes. Several allergens can be tested at the same time. Allergens are substances that cause an allergic reaction. Allergy skin prick or scratch test The intradermal skin test involves: Injecting a small amount of allergen into the skin. The provider then watches for a reaction at the site. This test is more likely to be used to find out if you're allergic to bee venom or penicillin. Or it may be used if the skin prick test was negative and the provider still thinks that you're allergic to the allergen. Intradermal allergy test reactions Patch testing is a method to diagnose the cause of skin reactions that occur after the substance touches the skin: Possible allergens are taped to the skin for 48 hours. The provider will look at the area in 72 to 96 hours.Before any allergy testing, the provider will ask about: Illnesses Where you live and work Lifestyle Foods and eating habits Allergy medicines can change the results of skin tests. Your provider will tell you which medicines to avoid and when to stop taking them before the test.Skin tests may cause very mild discomfort when the skin is pricked. You may have symptoms such as itching, a stuffy nose, red watery eyes, or a skin rash if you're allergic to the substance in the test. In rare cases, people can have a whole-body allergic reaction (called anaphylaxis ), which can be life threatening. This usually only occurs with intradermal testing. Your provider will be prepared to treat this serious response.Allergy tests are done to find out which substances are causing your allergy symptoms. Your provider may order allergy skin tests if you have: Hay fever ( allergic rhinitis ) and asthma symptoms that are not well controlled with medicine Hives and angioedema Food allergies Skin rashes ( dermatitis ), in which the skin becomes red, sore, or swollen after contact with the substance Penicillin allergy Venom allergy Allergies to penicillin and related medicines are the only drug allergies that can be tested using skin tests. Skin tests for allergies to other drugs can be dangerous. The skin prick test may also be used to diagnose food allergies. Intradermal tests are not used to test for food allergies because of high false-positive results and the danger of causing a severe allergic reaction.A negative test result means there were no skin changes in response to the allergen. This negative reaction most often means that you are not allergic to the substance. In rare cases, a person may have a negative allergy test and still be allergic to the substance.A positive result means you reacted to a substance. Your provider will see a red, raised area called a wheal. Often, a positive result means the symptoms you're having are due to exposure to that substance. A stronger response means you are likely more sensitive to the substance. People can have a positive response to a substance with allergy skin testing, but not have any problems with that substance in everyday life. Skin tests are usually accurate. But, if the dose of allergen is large, even people who are not allergic will have a positive reaction. Your provider will consider your symptoms and the results of your skin test to suggest lifestyle changes you can make to avoid substances that may be causing your symptoms.Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test; Allergic rhinitis - allergy testing; Asthma - allergy testing; Eczema - allergy testing; Hayfever - allergy testing; Dermatitis - allergy testing; Allergy testing; Intradermal allergy testing.Allergic rhinitis - what to ask your doctor - adult Allergic rhinitis - what to ask your doctor - child.RAST test RAST test Allergy skin prick or scratch test Allergy skin prick or scratch test Intradermal allergy test reactions Intradermal allergy test reactions Skin testing, PPD (R arm) and Candida (L) Skin testing, PPD (R arm) and Candida (L).Chiriac AM, Bousquet J, Demoly P. In vivo methods for the study and diagnosis of allergy.