Allergy Overview

What are allergies?

Allergies are due to a problem with the body's immune system. Most allergic reactions happen when the immune system reacts to a false alarm. Normally the immune system attacks harmful things, such as viruses or bacteria. But sometimes it overreacts and responds to things that are normally harmless. These may include dust, mold, pollen, or food.

What causes allergies?

Allergens are substances that can be breathed or swallowed, or that come in contact with the skin.

Allergic reaction symptoms will differ based on the type and amount of allergen you have come in contact with. It also depends on how your body’s immune system reacts to that allergen. Symptoms can range from mild itching or runny nose to a severe allergic reaction (anaphylaxis) that becomes a medical emergency.

The most common allergens are:

• Pollen

• Mold

• Household dust, dust mites, and their waste

• Animal dander, urine, or oil from skin

• Chemicals used for manufacturing

• Food

• Medicine

• Feathers

• Bee stings

• Cockroaches and their waste

• Latex

What are allergy symptoms?

An allergic reaction can happen anywhere in the body. This includes the skin, eyes, stomach lining, nose, sinuses, throat, and lungs. These are the places where immune system cells are found to fight off germs that are breathed in, swallowed, or come in contact with the skin. Allergic reactions can cause these symptoms:

• Stuffy nose, sneezing, itching, or runny nose, and itching in ears or roof of mouth

• Red, itchy, watery eyes

• Red, itchy, dry skin

• Hives or itchy welts

• Itchy rash

• Asthma symptoms, such as shortness of breath, coughing, or wheezing

• Anaphylaxis, a severe, life-threatening reaction

The symptoms of allergy sometimes look like other conditions or health problems. Always see your healthcare provider for a diagnosis.

How are allergies diagnosed?

To diagnose an allergy, your healthcare provider will give you an exam and review your health history. They will ask about allergens you come in contact with and what things make your symptoms better or worse. Your provider may also order these tests: Skin test, Blood test, Challenge test.

How are allergies treated?

Treatment will depend on what you are allergic to and your symptoms, age, and general health. It will also depend on how severe the condition is.

Allergy immunotherapy (shots or sublingual immunotherapy) and medicine are effective ways to treat allergies.

Medicine

For people who suffer from allergies, there are many medicines that work well. Nasal sprays work to decrease nasal congestion, stuffiness, and postnasal drip. Antihistamines are helpful for itchiness and hives. Decongestants are used to treat stuffiness in the nose and other symptoms linked to colds and allergies. But overuse of decongestants can be linked to rebound congestion or high blood pressure. Using medicines for asthma or allergy breathing symptoms is tailored for each person based on the severity of the symptoms.

Talk with your healthcare provider for more information about allergy medicines.