A food allergy occurs when the immune system mistakenly identifies a protein in a specific food as a threat, triggering a protective response that can cause symptoms ranging from mild to life-threatening. Hen’s egg allergy is the second most common food allergy in infants, following cow’s milk allergy, affecting approximately 1.3% of children under five years old. Parents are often concerned about the safest way to introduce eggs and assess their baby’s tolerance. True allergy testing involves complex clinical procedures that should never be attempted at home, but parents can follow specific guidelines for safe introduction and observation.
Recognizing the Signs of an Egg Allergy
Parents must understand the range of potential reactions, as symptoms of an egg allergy typically appear immediately or within two hours of ingestion. Reactions are broadly categorized into mild and severe, often involving the skin, gastrointestinal tract, or respiratory system.
Mild symptoms frequently involve the skin, such as hives (raised, red, itchy welts) or redness around the mouth, face, or neck. Gastrointestinal distress may also occur, including vomiting, nausea, or stomach cramping. These reactions are usually uncomfortable but do not immediately endanger the child’s life.
A severe reaction, known as anaphylaxis, is a rapid and potentially fatal event requiring immediate emergency intervention. Signs of anaphylaxis include difficulty breathing, wheezing, or a persistent cough, indicating airway compromise. Swelling of the tongue or throat, paleness, floppiness, or a sudden change in behavior can also signal this severe reaction. Anaphylaxis is defined by the involvement of two or more body systems, even if some symptoms are individually mild.
Safe Egg Introduction Guidelines
Parents often use the term “testing” when they mean “introducing” a potentially allergenic food for the first time. True allergy testing is reserved for medical professionals, but a careful home introduction is the standard procedure for healthy infants. Current medical guidance recommends introducing highly allergenic foods, including eggs, early in a baby’s diet, typically around six months of age, once they are ready for solids. This early and regular exposure may help reduce the risk of developing a food allergy.
The egg must be well-cooked for the first introduction to reduce the risk of foodborne illness and ensure the protein is altered by heat. Well-cooked forms, such as fully scrambled or hard-boiled eggs mashed into a puree, are recommended because heat changes the protein structure. Offer both the egg white and the yolk, since allergy-triggering proteins are present in both.
The first exposure should involve a very small amount, such as a quarter teaspoon, mixed into a food the baby has already tolerated. After the initial small taste, parents should watch the baby closely for the next five to ten minutes for any signs of immediate reaction. If no symptoms develop, the rest of the age-appropriate portion can be offered. After the first successful introduction, eggs should be kept in the baby’s regular diet, ideally two or more times a week, to maintain tolerance.
When introducing eggs, offer it as a single new food; no other new foods should be introduced for three to five days afterward. This observation period ensures that if a reaction occurs, the egg is clearly identified as the trigger. Delayed introduction of allergenic foods offers no benefit and may increase the chance of developing an allergy later.
When to Seek Professional Allergy Testing
A professional allergy evaluation becomes necessary if a baby has a previous reaction to egg, has moderate to severe eczema, or has a strong immediate family history of food allergies. These circumstances indicate a higher risk, and a pediatrician or allergist can determine the safest introduction plan or the need for formal testing.
The initial diagnostic steps typically include a detailed medical history review, followed by specific clinical tests. A skin prick test involves placing a drop of liquid containing egg protein onto the skin, which is then lightly pricked; a raised wheal indicates a potential allergy. Blood tests measure the level of Immunoglobulin E (IgE) antibodies, which reflect the immune system’s reaction to the egg protein.
The most definitive diagnostic tool is the supervised oral food challenge, conducted in a medical setting with emergency equipment on hand. During this challenge, the child is given gradually increasing amounts of the suspected food while being closely monitored by an allergist. This is the only test that can confirm whether a child has outgrown an allergy or can tolerate a specific food form, such as baked egg.
Emergency Protocol for Severe Reactions
If a severe allergic reaction (anaphylaxis) is suspected, immediate action is required, as delays in treatment can have serious consequences. Epinephrine is the first-line treatment for anaphylaxis and should be administered right away if a severe reaction is apparent or if two or more body systems are involved. Parents of at-risk infants should have an epinephrine auto-injector prescribed and a written emergency action plan.
After administering the epinephrine into the mid-outer thigh, emergency medical services should be called immediately. The child should be laid flat with their legs elevated. However, if the child is vomiting or having difficulty breathing, they should be placed on their side or allowed to sit up. Even if symptoms improve following the injection, the child must be transported to the emergency room for observation, as symptoms can return hours later in a “biphasic” reaction.