An egg allergy is a common type of food allergy that occurs when a person’s immune system overreacts following exposure to eggs or egg derivatives (egg whites, egg yolks or egg proteins).

Eggs are one of the six foods that account for 90 percent of food-related allergic reactions in children, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). Egg allergies typically begin in infancy, and most children who develop an early egg allergy will outgrow the condition by the age of 5 or 6.

Food allergies themselves are rare, occurring in about 6 to 8 percent of children and about 2 percent of adults. Susceptible children or adults who have been exposed to an egg allergen, usually by eating it, will typically display symptoms within a few minutes to a few hours. Symptoms frequently include itchiness, rashes, hives, stomach cramps, nausea and breathing problems. Severe reactions to eggs may result in a potentially life–threatening condition known as anaphylactic shock.

Egg allergies occur when an egg component triggers an allergic response. The immune system mistakes the egg for a harmful substance and releases antibodies called immunoglobulin E (IgE) in response. As a defense against the invader, the IgE antibodies cause certain histamines to be released into the blood stream. These histamines result in the unpleasant allergic symptoms most people associate with egg allergies.

Egg and egg derivatives are found in a broad variety of substances, and only a trace amount of egg is needed to trigger an allergic attack in some individuals. Sensitive individuals need to be aware of the many types and names of egg products and egg derivatives.

In some instances a person can be allergic to the gases given off by eggs during cooking. This condition usually triggers cases of allergic rhinitis (hay fever), the inflammation of mucous membranes lining the nose after an allergic reaction. Symptoms associated with this condition include runny nose, stuffy head, nasal congestion and sinus pressure.

While most people are allergic to the whites of eggs, a few rare people find they are allergic to proteins found in the yolk. These individuals will experience an allergic reaction to both egg yolks and inhaled or ingested bird antigens (usually from feather particles, dried airborne droppings and meat). This condition is known as bird-egg syndrome.

Some individuals find they are only seasonally allergic to eggs. This usually occurs in people who have allergies to oak pollen, short and western ragweed, and the goosefoot family of weeds. When these allergens are in season, some people may find they also have a cross-reaction with eggs. This occurs because the proteins in the airborne allergens are similar enough to those in eggs that the body confuses the two.