The American College of Allergy, Asthma, and Immunology reports that 10 percent of the U.S. population has an allergy to exotic or household animals. Although dog and cat allergies are the most common animal-related allergy, an allergy to feathers or down can cause mild to severe asthma-like symptoms. Down feather allergies can be managed through medication and lifestyle changes.
All allergies are caused by a body's overproduction of immunoglobulins, proteins that are designed to target infections so that the immune system can destroy them. A person with an allergy develops immunoglobulins that are sensitive to materials or substances, such as down or feathers, that may not affect other people with more controlled immunoglobulins.
Allergies to birds or feathers may be triggered by several sources. A person can be allergic to feather or down, the small, fluffy feathers that make up the base of the feather. When a person comes into physical contact with down from a direct source such as a bird or an indirect source like a down pillow, her sensitive immunoglobulins trigger an allergic reaction to alert her body to a potential infection.
The most common symptoms suffered by people with down allergies are runny nose, watery eyes, itching skin or respiratory distress. Persistent skin irritation can lead to a chronic condition such as eczema. Severe allergies to down feathers could cause a life-threatening asthma attack in which a person's airway swells, restricting air flow to the lungs and other vital body organs.
In most cases, a doctor can diagnose a down allergy simply by reviewing a patient's symptoms and coordinating those symptoms to an exposure to down. A patient can also undergo an allergy test to rule out other allergies.
In a skin prick test, a doctor uses a small pin or needle to inject a small amount of a concentrated down serum or extract under the patient's skin. Usually skin prick tests are done on the patient's back. If the patient is allergic to the down, the skin will react and a rash will appear.
A serum allergen test requires mixing the patient's blood in a matrix that includes down serum; the mixture is then examined under a microscope to observe the rate at which the immunoglobulins in the blood attach to the allergen in the matrix. A high rate of attachment indicates an allergy.
Down allergies can be managed by avoiding sources of down feathers including farm fowls, birds, down comforters and feather pillows. Install air filtration systems in the home to remove down from the air. Some down allergies can be managed with over-the-counter or prescription allergy medication that suppresses the symptoms of allergic reactions. Allergy shots contain low levels of down serum; they are injected during a period of several months to help the body build up an immunity. Allergy shots do not guarantee complete allergy relief, however.
Most people with down allergies are not allergic to other bird byproducts. People with down allergies do not need to avoid meat or eggs from chickens or other birds. Some people who believe they have down allergies are actually allergic to dust mites that live in down pillows or comforters. An allergy test can determine the true cause of a suspected allergy to down.