egg allergy

Egg Allergy: A Common Food Allergy

An egg allergy occurs when the body's immune system overreacts to proteins in egg whites and/or yolks, causing an allergic reaction. This reaction can range from mild symptoms such as hives and hay fever to severe reactions like anaphylaxis.

• Symptoms: The symptoms of an egg allergy can include:
  • Abdominal pain, diarrhea, nausea, vomiting, stomach cramps
  • Hives (allergic urticaria), itching, eczema
  • Wheezing, nasal congestion, coughing, hoarseness, throat tightness
  • Itchy, watery eyes
• Onset: Symptoms usually occur a few minutes to a few hours after eating eggs or foods containing eggs.
• Prevalence: Egg allergy is the second most common food allergy in children and affects around 2% of children. However, most children will outgrow their egg allergy by age 5-6.

Causes and Triggers

An egg allergy develops when the body's immune system becomes sensitized to proteins in egg whites and/or yolks. This can occur due to various factors, including:

• Genetic predisposition: Some people may be more prone to developing an egg allergy due to their genetic makeup.
• Environmental factors: Exposure to eggs or egg products at a young age may trigger an allergic reaction.

Treatment and Management

While there is no cure for an egg allergy, symptoms can be managed through:

• Avoiding eggs and egg products: The most effective way to manage an egg allergy is to avoid consuming eggs and egg products altogether.
• Medications: Antihistamines or epinephrine injections may be prescribed to treat mild to severe allergic reactions.

References

[1] Egg allergy develops when the body’s immune system becomes sensitized and overreacts to proteins in egg whites and/or yolks. When eggs are eaten, the body sees the protein as a foreign invader and sends out chemicals to defend against it. Those chemicals cause the symptoms of an allergic reaction. [Context 1]

[2] Egg allergy is the second most common food allergy in children. But healthcare providers estimate that around 2% of children are allergic to eggs, so it’s still relatively rare. It’s more common in children than adults. However, around half of children will develop an egg tolerance by age 5, and up to 70% will outgrow their egg allergy by [Context 2]

[3] Egg allergies are among the most common IgE-mediated food allergies in children. Fortunately, the majority of children with egg allergy will outgrow it. Children who are allergic to eggs typically display symptoms within minutes to hours of eating eggs or foods containing eggs. Symptoms can range from mild to severe and may include difficulty [Context 3]

[4] Hen’s egg allergy is among the most common food allergies in infants and young children, but is less common in older children and adults. Most children eventually outgrow their allergy to eggs by [Context 4]

[5] Egg yolk allergies are more likely to affect adults, while egg white allergies tend to affect children. If you have an egg white allergy, healthcare providers also suggest avoiding the yolk. [Context 12]

Diagnosing Egg Allergy: A Comprehensive Overview

Egg allergy diagnosis involves a combination of clinical history, physical examination, and laboratory tests to confirm the presence of an allergy. Here are some key diagnostic tests used to diagnose egg allergy:

• Skin Prick Test (SPT): This is a safe, low-risk test that exposes the skin to small amounts of egg proteins. A positive reaction indicates an allergy [3][4].
• Blood Tests: In vitro serum testing for IgE antibodies provides an indication of the immune response to allergens associated with allergic disease [7]. The Whole Egg Allergy IgE Blood Test measures IgE antibody levels in the blood to detect an allergy to egg yolks and whites [6].
• Oral Food Challenge (OFC): This is considered the "gold standard" for diagnosing egg allergy, where a patient consumes increasing amounts of egg under medical supervision. A positive reaction indicates an allergy [13][15].

Other Relevant Information

• The prevalence of hen's egg allergy confirmed by oral challenge was 1.6% of children three years of age in an unselected population in Denmark [11].
• Egg allergy affects 0.5 to 2.5% of young children, according to a meta-analysis of the prevalence of food allergy [11].

References

[3] Skin prick test: This is a safe, low-risk test that exposes the skin to small amounts of egg proteins. [4] A positive reaction indicates an allergy. [6] The Whole Egg Allergy IgE Blood Test measures IgE antibody levels in the blood to detect an allergy to egg yolks and whites. [7] In vitro serum testing for IgE antibodies provides an indication of the immune response to allergens associated with allergic disease. [11] The prevalence of hen's egg allergy confirmed by oral challenge was 1.6% of children three years of age in an unselected population in Denmark. [13] Oral Food Challenge (OFC): This is considered the "gold standard" for diagnosing egg allergy, where a patient consumes increasing amounts of egg under medical supervision. [15] A positive reaction indicates an allergy.

Current Treatment Options for Egg Allergy

Egg allergy is a common food allergy that can cause severe reactions in some individuals. While there is no cure for egg allergy, several treatment options are available to manage symptoms and prevent reactions.

• Antihistamines: Antihistamines may help relieve mild symptoms of egg allergy, such as itching. However, they do not provide long-term protection against allergic reactions [4].
• Epinephrine (Adrenaline): In severe cases of egg allergy, epinephrine is the first line of treatment to prevent anaphylaxis. It should be administered immediately in case of a severe reaction [8].

New Developments in Egg Allergy Treatment

Recently, a new medication has been approved for the treatment of egg allergy.

• Xolair (Omalizumab): Xolair is the first FDA-approved medication to reduce allergic reactions to more than one type of food after accidental exposure. It has been shown to be effective in 67% of people allergic to eggs, 66% of people allergic to milk, and 42% of people allergic to peanuts [3][6]. Xolair works by blocking the action of IgE antibodies, which are responsible for triggering allergic reactions.

Important Considerations

If you experience a severe egg allergy reaction, it is essential to call 911 immediately. In less severe cases, antihistamines can help reduce symptoms after exposure to eggs [4].

References:

[3] Feb 18, 2024 — The study also found that Xolair was effective after 4 to 5 months in 67% of people allergic to eggs; 66% of people allergic to milk; and 42% of people allergic to peanuts. [4] If you experience a severe egg allergy reaction, call 911 immediately. In less severe cases, antihistamines can reduce the symptoms after exposure to eggs. [6] Feb 16, 2024 — FDA approves Xolair® (omalizumab) as first and only medicine for children and adults with one or more food allergies. [8] Antihistamines may help to relieve mild symptoms of egg allergy, such as itching. In addition, your allergist may prescribe epinephrine (adrenaline) in an auto-injector.

Differential Diagnosis of Egg Allergy

Egg allergy can often be confused with other conditions, making differential diagnosis crucial for accurate diagnosis and treatment. Here are some possible differential diagnoses to consider:

• Other immunologic adverse food reactions: These include allergies to other foods such as milk, soy, wheat, or peanuts [3][6].
• Nonimmunologic adverse food reactions: These can include gastrointestinal upset, intolerance, or other non-allergic reactions to food [3][6].
• Reactions involving the gut: Such as celiac disease (sprue), acute gastritis, or bulimia nervosa [4].

Key Considerations

When considering differential diagnoses for egg allergy, it's essential to rule out other conditions that may present with similar symptoms. This can include:

• Cross-reactivity: Allergies to other bird eggs (turkey, duck, goose, seagull, and quail) have been reported [1].
• Non-IgE mediated allergies: These can be considered when routine diagnostic parameters (skin tests, antigen-specific IgE) are uninformative [14].

Diagnostic Tools

The gold standard diagnostic tool for egg allergy remains an oral food challenge under medical supervision. In daily practice, a clinical history of an allergic reaction occurring after ingestion of egg, together with positive testing (egg skin prick test or egg-specific IgE), is usually used for diagnosis [15].

References

[1] Cross-reactivity between hen's egg and other bird eggs has been reported. [3] Other immunologic adverse food reactions should be considered in the differential diagnosis. [4] Acute gastritis, bulimia nervosa, and celiac disease (sprue) are possible differential diagnoses. [6] Nonimmunologic adverse food reactions can present with similar symptoms to egg allergy. [14] Non-IgE mediated allergies may be considered when routine diagnostic parameters are uninformative. [15] The gold standard diagnostic tool for egg allergy remains an oral food challenge under medical supervision.