|Allergy is a reaction of immune system produced by our body in response to environmental factors, drugs and foods. It is also called hypersensitivity. The immune system is a system that defends the body against foreign invaders. Substances that often cause reactions are: Pollen, Dust mites, Insect strings, Medicines and foods. Allergies can cause a variety of symptoms such as a running nose, sneezing, itching, rashes, swelling, or asthma. The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis - a potentially life-threatening emergency. To evaluate whether you have an allergy or not skin and blood tests are done. The most common test for respiratory, penicillin, insect sting, skin, and food allergies is a skin prick or scratch test. A small amount of the allergen is lightly scratched on the skin using a small plastic device, and the doctor watches for swelling, itchiness, and redness in the skin at the site of the scratch. Other tests look for certain markers in the blood such as IgE antibodies associated with allergies. Allergy treatments include: Allergen avoidance: In this allergen is identified and contact with the allergen is avoided. Medications to reduce symptoms: Allergy medications can help reduce your immune system reaction and ease symptoms.Immunotherapy: For severe allergies or allergies not completely relieved by other treatment, allergy shots may be recommend (immunotherapy). This treatment involves a series of injections of purified allergen extracts, usually given over a period of a few years. Emergency epinephrine: An emergency epinephrine shot is given for severe allergic reactions, an epinephrine shot can reduce symptoms until you get emergency treatment. Some herbs can help in treating allergies: Like Butter bur may help relieve symptoms of allergic rhinitis. Milk thistle may improve symptoms of allergic rhinitis. Phleumpratense may help relieve symptoms associated with asthma.