Egg allergy reactions vary from person to person and usually occur soon after exposure to egg. Egg allergy symptoms can include:

• Skin inflammation or hives — the most common egg allergy reaction

• Nasal congestion, runny nose and sneezing (allergic rhinitis)

• Digestive symptoms, such as cramps, nausea and vomiting

• Asthma signs and symptoms such as coughing, wheezing, chest tightness or shortness of breath

Anaphylaxis

A severe allergic reaction can lead to anaphylaxis, a life-threatening emergency that requires an immediate epinephrine (adrenaline) shot and a trip to the emergency room. Anaphylaxis signs and symptoms include:

• Constriction of airways, including a swollen throat or a lump in your throat that makes it difficult to breathe

• Abdominal pain and cramping

• Rapid pulse

• Shock, with a severe drop in blood pressure felt as dizziness, lightheadedness or loss of consciousness

Discuss with your doctor any reaction — no matter how mild — you or your child has to eggs. The severity of egg allergy reactions can vary each time one occurs, so even if a past reaction was mild, the next one could be more serious.

If your doctor thinks you or your child may be at risk of a severe reaction, he or she may prescribe an emergency epinephrine shot to be used if anaphylaxis occurs. The shot comes in a device that makes it easy to deliver, called an autoinjector.

An immune system overreaction causes food allergies. For egg allergy, the immune system mistakenly identifies certain egg proteins as harmful. When you or your child comes in contact with egg proteins, immune system cells (antibodies) recognize them and signal the immune system to release histamine and other chemicals that cause allergic signs and symptoms.

Both egg yolks and egg whites contain proteins that can cause allergies, but allergy to egg whites is most common. It's possible for breast-fed infants to have an allergic reaction to egg proteins in breast milk if the mother consumes eggs.

Certain factors can increase the risk of developing an egg allergy:

• Atopic dermatitis. Children with this type of skin reaction are much more likely to develop a food allergy than are children who don't have skin problems.

• Family history. You're at increased risk of a food allergy if one or both of your parents have asthma, food allergy or another type of allergy — such as hay fever, hives or eczema.

• Age. Egg allergy is most common in children. With age, the digestive system matures and allergic food reactions are less likely to occur.

The most significant complication of egg allergy is having a severe allergic reaction requiring an epinephrine injection and emergency treatment.

The same immune system reaction that causes egg allergy can also cause other conditions. If you or your child has an egg allergy, you or your child may be at increased risk of:

• Allergies to other foods, such as milk, soy or peanuts

• Allergies to pet dander, dust mites or grass pollen

• Allergic skin reactions such as atopic dermatitis

• Asthma, which in turn increases the risk of having a severe allergic reaction to eggs or other foods