Allergies are a common class of ailments which, according to the American Academy of Allergy Asthma and Immunology, affect approximately 50 million Americans each year. Allergies are triggered by special molecules called allergens. Allergies can be treated in a variety of ways, including injections, medications and avoidance of the allergens themselves.
Mechanism of Allergies
Allergies are the the result of an abnormal reaction from the immune system when the body is exposed to a molecule known as an allergen, according to the American Academy of Allergy Asthma and Immunology. Allergens are substances that are normally harmless; however, patients with allergies have an immune system that identifies these molecules as dangerous. Consequently, the immune system produces special proteins called IgE antibodies, which are designed to respond to these allergens. When an IgE antibody encounters the allergen for which it was designed, it causes a series of reactions which lead to inflammation and activation of the immune system, which results in the allergic reaction.
Common Allergens
Allergens are any substance which can trigger an immune reaction. There are certain substances that can cause allergic reactions in many people, Family Doctor explains. Pollen, which can come from grass, weeds and trees, can cause people to have seasonal allergies; tree pollen most typically affects people in the spring, whereas weeds and grasses can lead to summer allergies. Ragweed can also cause allergies to occur in the fall. People can also have allergies to mold, dander from pets and dust, which contains a variety of potential allergens.
Symptoms
The symptoms of an allergic reaction depend on the type of allergen and its route of entry. Inhaled allergens, for example, typically cause congestion and an itchy or runny nose, the Mayo Clinic explains. Allergies to things that come into contact with the skin can cause itchy and flaking skin as well as a rash. Food allergies can cause hives, a tingling of the mouth, swelling of the lips and tongue and anaphylaxis. Anaphylaxis is a dangerous allergic reaction that can cause lightheadedness, swollen airways, a rash, loss of consciousness and a rapid pulse. Insect stings can cause swelling of the area around the sting, hives, shortness of breath and anaphylaxis. Finally, allergies to certain drugs can also lead to anaphylaxis as well as hives, itchy skin, shortness of breath/chest tightness, and a rash.
Diagnosis
One way in which an allergy can be diagnosed is via a skin prick test. With a skin prick test, a small amount of several different potential allergens is placed on the skin in a row. Each allergen is then inserted just below the skin's surface by pricking the skin. If the patient has an allergy to one of the compounds, the area around the prick of the allergen will swell and turn red. Blood tests can also be done to look for IgE antibodies to common allergens.
Treatment
The easiest way to treat an allergy is to identify and avoid the allergen. Patients can also take medications, such as corticosteroids, antihistamines, decongestants and compounds which suppress the immune system, to relieve the symptoms of allergies. Immunotherapy, which consists of a series of injections of purified allergens, can be used to desensitize the body to the allergen. These shots are given over the course of a few years by a trained specialist. Patients with severe allergies that cause anaphylaxis may need to keep an epinephrine pen on them at all times in the event of anaphylaxis, as this drug can help counteract this life-threatening immunological response.
