food allergy

A food allergy occurs when your immune system overreacts to a harmless food protein, known as an allergen [1]. This can happen with any type of food, but some foods are more likely to cause an allergic reaction than others.

The nine most common food allergens in the U.S. include milk, egg, fish, Crustacean shellfish, tree nuts, peanuts, wheat, and soybeans [2]. When you have a food allergy, your immune system identifies these harmless proteins as a danger and triggers a protective response, which can lead to a range of symptoms.

Symptoms of a food allergy can vary from person to person but may include:

• A raised, itchy red rash
• Swelling of the face, eyes, lips, and tongue
• Shortness of breath
• Digestive discomfort

In severe cases, a food allergy can progress to anaphylaxis, a life-threatening condition that requires immediate medical attention [7]. If you suspect you or someone else has a food allergy, it's essential to consult with a healthcare professional for proper diagnosis and treatment.

It's worth noting that a food allergy is different from having a food intolerance. While both conditions can cause symptoms after eating certain foods, the immune system response is different in each case [3]. Food intolerances typically do not involve an allergic reaction and may be caused by other factors such as enzyme deficiencies or sensitivity to specific ingredients.

References: [1] - A food allergy happens when your immune system overreacts to a harmless food protein—an allergen. [2] - The nine most common food allergens are milk, egg ... [3] - Information: A food allergy is different from having a food intolerance [7] - While most symptoms from food allergies are mild and limited to skin or digestive discomfort, some may progress to a severe, life-threatening ...

Common Signs and Symptoms of Food Allergy

Food allergies can cause a range of symptoms, from mild discomfort to life-threatening reactions. Here are some common signs and symptoms to look out for:

• Skin symptoms: Hives or red, itchy skin [1], swelling of the lips, face, eyes [6]
• Mouth symptoms: Tingling mouth [1], itchy mouth [5]
• Respiratory symptoms: Stuffy or itchy nose, sneezing [8], difficulty breathing (in severe cases) [2]
• Gastrointestinal symptoms: Abdominal pain, vomiting, diarrhea, bloody stools [9]
• Cardiovascular symptoms: Weak pulse, pale or blue coloring of skin, dizziness [4]

Severe Symptoms: Anaphylaxis

In rare but serious cases, food allergies can trigger anaphylaxis, a life-threatening condition that requires immediate medical attention. Signs and symptoms include:

• Swelling of the tongue, affecting the ability to talk or breathe [4]
• Difficulty swallowing
• Weak pulse
• Pale or blue coloring of skin
• Dizziness

Important Note

If you experience any of these severe symptoms, seek emergency medical help immediately. Call 911 or visit the ER if you suspect anaphylaxis.

References:

[1] - Context result 1: Tingling or itching in the mouth. [2] - Context result 2: Eating foods you're allergic to can cause hives, airway swelling... [3] - Context result 3: Nose: itchy or runny nose, sneezing; Mouth: itchy mouth; [4] - Context result 4: Tight, hoarse throat; trouble swallowing; Swelling of the tongue... [5] - Context result 5: Oct 2, 2024 — The most common nose, eye, and throat symptoms include a runny nose... [6] - Context result 6: Symptoms of food allergy · swelling of lips, face, eyes [7] - Context result 7: Symptoms of anaphylaxis generally include two or more of the following body systems: [8] - Context result 8: ... food, though they can sometimes appear a few hours later. [9] - Context result 9: What Are the Symptoms of a Food Allergy? Symptoms of a food allergy can include...

Diagnosing Food Allergies: A Comprehensive Overview

Food allergies are a type of immune system disorder that can cause severe reactions to specific foods. Diagnosing food allergies requires a combination of medical history, physical examination, and various tests. Here's an overview of the diagnostic tests used to determine food allergies:

• Skin Prick Test (SPT): This is a common test used to diagnose food allergies. A small amount of the suspected allergen is placed on the skin, and the reaction is observed. If you react to the allergen, it may indicate an allergy [1].
• Blood Tests: Blood tests measure the level of IgE antibodies in your blood, which can indicate a food allergy. The most common blood test is the RadioAllergoSorbent Test (RAST) [2]. Another type of blood test is the Enzyme-Linked Immunosorbent Assay (ELISA) [3].
• Oral Food Challenge (OFC): This is considered the gold standard for diagnosing food allergies. In this procedure, a small amount of the suspected allergen is consumed under medical supervision to accurately diagnose or rule out a true food allergy [4]. However, it's a time-consuming and requires highly trained personnel.
• Intradermal Skin Test: This test involves injecting a small amount of the allergen into the skin. It's not commonly used for diagnosing food allergies due to its low accuracy and potential risks [5].
• Atopy Patch Test (APT): This is a less common test that involves placing a small amount of the suspected allergen on the skin, usually on the back or arm. The reaction is observed over time [6].

What's Next?

After your tests are done, you'll need to work together with your doctor to get the right diagnosis. They will interpret the test results and use them to aid in a diagnosis. It's essential to note that no single test can definitively diagnose food allergies; a combination of medical history, physical examination, and various tests is usually required [7].

References:

[1] Boyce JA, et al. Guidelines for the diagnosis and management of food allergy in the United States: Report of the NIAID-sponsored expert panel.

[2] Food Allergy Symptoms ... Skin testing is the most common and quickest food allergy test.

[3] A blood sample is taken and then mixed with that allergen. Blood tests measure the level of IgE in the blood.

[4] The gold standard for diagnosing food allergy is an oral food challenge.

[5] Intradermal skin tests — Intradermal skin testing should not be performed in the evaluation of food allergy, since it does not add to the diagnosis and carries a greater risk of inducing a ...

[6] Less commonly used allergy testing is typically done by an allergist and includes intradermal tests, atopy patch ...

[7] Diagnosis of food allergy starts with a detailed, allergy-focused history.

Current Drug Treatments for Food Allergy

There are several drug treatments being studied or approved for the treatment of food allergy. One such medication is Xolair (omalizumab), which has been FDA-approved to reduce allergic reactions to more than one type of food after accidental exposure [1][6]. This injectable prescription medicine is used to treat food allergy in people 1 year of age and older, reducing the risk of anaphylaxis and other severe allergic reactions [2].

Other Treatments Being Studied

Additional treatments currently being studied as potential options for food allergy include oral immunotherapy (OIT) and sublingual immunotherapy. These therapies involve gradually introducing small amounts of the allergenic food into the body to build tolerance over time [3]. While these treatments show promise, they are still in the experimental stages and require further research.

Monoclonal Antibodies

Another area of research involves monoclonal antibodies, such as omalizumab, which targets IgE, a protein involved in allergic reactions. Studies have shown that this treatment can be effective in reducing food allergy symptoms [4].

Current FDA Approval

As of now, Xolair (omalizumab) is the only medication approved by the FDA for the treatment of food allergy. It has been specifically approved to reduce IgE-mediated food allergies that may occur due to accidental exposure [6]. This approval marks a significant step forward in the management of food allergy.

References

[1] Xolair's FDA approval for treating multiple food allergies. [2] Description of XOLAIR's use in treating food allergy. [3] Explanation of oral and sublingual immunotherapy as potential treatments. [4] Discussion of monoclonal antibodies, such as omalizumab, in treating food allergy. [5] Mention of FDA approval for Xolair to treat one or more food allergies in patients as young as 1 year old. [6] Description of Xolair's approval for reducing IgE-mediated food allergies due to accidental exposure.

Differential Diagnosis of Food Allergy

Food allergy is a complex condition that can be challenging to diagnose, and it requires a comprehensive approach to rule out other conditions that may mimic its symptoms. The differential diagnosis of food allergy involves considering various anatomical and digestive problems, as well as immunologically mediated diseases.

Conditions to Consider

Some of the conditions that should be considered in the differential diagnosis of food allergies include:

• Auriculotemporal syndrome
• Esophagitis
• Factitious disorder
• Food poisoning
• Acute gastritis
• Pancreatic insufficiency
• Shwachman-Diamond syndrome
• Pyloric stenosis
• Hirschsprung’s disease
• Tracheoesophageal fistula
• Gall bladder disease
• Hiatus hernia
• Gastric reflux
• Gastric ulcers
• Cancer
• Irritable bowel syndrome

Immunologically Mediated Diseases

In addition to these anatomical and digestive problems, immunologically mediated diseases such as lactose intolerance should also be considered in the differential diagnosis of food allergies.

Importance of Accurate Diagnosis

Accurate diagnosis is crucial in managing food allergy, as it can help prevent misdiagnosis and inappropriate treatment. A multi-disciplinary approach involving healthcare professionals from various specialties may be necessary to establish a correct diagnosis.

References:

• Liotti L, Beghetti I, Piccinno V, Serra L, Bottau P. Component-Resolved Diagnosis in Food Allergies. Medicina (Kaunas). Aug 18, 2019. [QxMD ...]
• Silbermann A, et al. The differential diagnosis of food intolerance.
• Fiocchi A. The differential diagnosis of food allergy includes sepsis, other infectious diseases, acute gastrointestinal episodes, and surgical conditions.

Note: The above information is based on the search results provided in the context section.