Allergies

Allergies are very common and affect millions of Americans.

Allergies occur when the body's immune system reacts to an allergen. The reaction is called “hypersensitivity” and causes the body to release inflammatory proteins into the body. Allergens are any foreign substance that triggers the body's immune system to react defensively. Allergens include substances such as pollen, dust, pet dander, insect venom, mold, certain medications, and various foods.

Symptoms of an allergy or hypersensitivity reaction range from mild irritations such as sneezing, coughing, skin irritations, and a runny nose to more serious reactions such as indigestion, vomiting, and diarrhea. In some cases, an extreme, life-threatening reaction called anaphylaxis can occur in response to allergens; anaphylaxis can cause a patient's airway to swell and close, which prevents the person from breathing.

There is no specific cause of allergies. Family history, genetics, and environmental exposure to allergens all contribute to the risk of developing allergies.

Allergies cannot be completely cured, but there are treatments available to manage them and actions that can be taken to prevent reactions. Prescription and non-prescriptions medications, including antihistamines, are used to treat seasonal and pollen allergies. Long-term treatment of other allergies may require immunotherapy to allow the body to increase its tolerance to an allergen over time.

Allergies and hypersensitivity reactions are caused when the body's immune system release inflammatory proteins in response to an allergen. Since immune systems vary from person to person, allergies and allergic reactions differ greatly among individuals.One person's immune system may attack the allergen bee venom and another's may react to peanut ingestion.

An allergy starts when your immune system mistakes a normally harmless substance for a dangerous substance. The immune system then produces antibodies that remain alert for another exposure to that particular allergen. When you are exposed to the allergen again, these antibodies release immune system chemicals, such as histamine, that cause allergy symptoms.

The cause of allergies is largely unknown and it is difficult to predict who will develop allergies to particular substances.

You are more likely to develop allergies if you:

• Have a family history of asthma or allergies
• Are a child
• Have asthma or other allergies

See your doctor or pharmacist if symptoms interfere with daily life or are not controlled by over-the-counter medicines. Call 911 for signs of a severe reaction (anaphylaxis): trouble breathing, swelling of the face or throat, fainting, or a rapid, weak pulse.