Allergies are an exaggerated immune system response to a substance that is deemed a threat but is actually harmless. When this substance is inhaled, swallowed or comes into contact with the skin, the immune system defends the body by releasing chemicals that attack the invader. These chemicals cause unpleasant symptoms such as runny nose, itchiness, watery eyes, rashes, hives, etc.
There are hundreds of substances that can trigger allergies. They are called allergens and include pollen from plants and trees, mold, dust mites, animal dander, chemicals, foods and medications.
Allergies can affect people of all ages, races and lifestyles. They are most common in children, but can occur at any age. There does appear to be a genetic predisposition toward developing allergies; a child whose parent(s) suffer from allergies is more likely to experience them.
Certain types of allergies can be prevented by avoiding contact with the allergen. A person allergic to a specific food can eliminate it from his or her diet easily enough. Other allergens are difficult to avoid, though steps can be taken to limit exposure. These include staying indoors during peak pollen times, purchasing allergy-safe bedding and investing in a dehumidifier to reduce moisture.
The first step in testing for allergies is a physical examination and review of your medical history. Your doctor will ask questions about your symptoms. The allergen is identified through skin or blood testing.
Allergies can be treated through prevention, medication or immunotherapy. Prevention involves avoiding contact with the allergen that triggers your symptoms. Medications include antihistamines, decongestants, nasal sprays, eye drops and corticosteroids. Those who are unable to avoid allergy triggers and do not find relief from medications may be candidates for immunotherapy. This long-term treatment plan involves introducing small amounts of allergen into the body over a period of time in order to build up immunity. Immunotherapy may be administered in the form of injections (allergy shots) or orally (droplets under the tongue).