Food Allergies: Symptoms, Causes, and Treatment

What Are Food Allergies?

A food allergy occurs when the immune system mistakenly identifies specific proteins in food as harmful and triggers an allergic reaction. Over 170 foods can cause allergies, with common culprits including eggs, milk, peanuts, tree nuts, fish, shellfish, soy, and sesame.

Common Symptoms of Food Allergies

Symptoms of food allergies can appear within minutes to hours after consuming an allergen and range from mild to life-threatening.

Mild to Moderate Symptoms:

• Hives or skin rashes
• Red, itchy, or tingling sensations in the mouth or throat
• Runny nose and nasal congestion
• Coughing or wheezing
• Stomach pain, vomiting, or diarrhea

Severe Symptoms: Anaphylaxis

Anaphylaxis is a life-threatening reaction requiring immediate medical attention. Symptoms include:

• Throat swelling and difficulty breathing
• Severe drop in blood pressure
• Rapid heartbeat
• Loss of consciousness

Types of Food Allergies

Food allergies fall into two categories based on how the immune system reacts:

IgE-Mediated Food Allergies

These allergies involve immunoglobulin E (IgE) antibodies, which trigger the release of histamine and other chemicals, leading to symptoms such as swelling, itching, and difficulty breathing.

Non-IgE-Mediated Food Allergies

This type of allergy is driven by different immune responses, often affecting the digestive system. Symptoms may take longer to appear and primarily cause gastrointestinal distress.

What Causes Food Allergies?

Food allergies occur when the immune system incorrectly perceives certain food proteins as threats and releases chemicals to combat them. This overreaction results in allergy symptoms.

Some individuals are genetically predisposed to food allergies, and environmental factors, such as diet and exposure to allergens early in life, may also play a role.

Risk Factors for Developing Food Allergies

Certain factors increase the likelihood of developing food allergies:

• Family History: Having relatives with allergies increases the risk.
• Other Allergic Conditions: People with asthma, eczema, or hay fever are more susceptible.
• Age and Gender: Food allergies often develop in childhood and may be more common in males at birth but more frequent in adult females.
• Gut Microbiome Changes: A disrupted gut microbiome due to antibiotics, diet, or sterile environments may contribute to food allergies.

Diagnosing Food Allergies

A specialist known as an allergist-immunologist diagnoses food allergies through:

Medical History Review

Doctors assess dietary habits, symptom patterns, and reaction severity.

Allergy Testing

• Skin Prick Test: Small amounts of allergens are applied to the skin to check for reactions.
• Blood Test: Measures IgE antibodies associated with allergic responses.
• Elimination Diet: Involves removing potential allergens from the diet and gradually reintroducing them.
• Oral Food Challenge: A controlled test where small amounts of suspected allergens are consumed under medical supervision.

Treatment and Management of Food Allergies

Avoidance of Allergens

The most effective way to prevent allergic reactions is to avoid trigger foods. This includes:

• Carefully reading food labels
• Informing restaurants about allergies
• Avoiding cross-contact with allergens

Emergency Preparedness

Individuals with severe allergies should always carry an epinephrine auto-injector (EpiPen) to treat anaphylaxis. An anaphylaxis action plan should also be in place.

Medications for Allergy Management

• Antihistamines: Help relieve mild symptoms like itching and hives.
• Corticosteroids: Reduce severe allergic inflammation.

Oral Immunotherapy (OIT)

OIT gradually introduces small amounts of allergens to desensitize the immune system. Currently, Palforzia is the only FDA-approved treatment for peanut allergies.

Biologic Therapy

Xolair (omalizumab) is an injectable medication that blocks IgE antibodies, reducing allergic reactions and increasing tolerance to allergens.

Can Food Allergies Be Prevented?

While there is no guaranteed way to prevent food allergies, research suggests early exposure to allergens (such as peanuts) in infancy may reduce the risk.

Final Thoughts

Food allergies can significantly impact daily life, but with careful management, avoidance strategies, and medical treatments, individuals can prevent severe reactions and maintain a healthy lifestyle.

Frequently Asked Questions

1. Can you outgrow food allergies?
Yes, some children outgrow allergies to milk, eggs, and soy, but peanut, tree nut, and shellfish allergies often persist into adulthood.

2. How can I tell if I have a food allergy or intolerance?
A food allergy triggers an immune response, while an intolerance (such as lactose intolerance) mainly affects digestion without involving the immune system.

3. What should I do if I accidentally eat an allergen?
For mild symptoms, antihistamines may help, but for severe reactions, immediately use an epinephrine auto-injector and seek emergency medical help.

4. Is there a cure for food allergies?
There is no cure, but treatments like oral immunotherapy and biologic therapy can help reduce allergic reactions.

5. Are food allergies the same as food sensitivities?
No, food allergies involve an immune response, while food sensitivities may cause digestive discomfort without triggering the immune system.