Food Allergy

Introduction

  • Food allergy is an immune system reaction triggered by specific foods. Even a small amount of the allergenic food can cause symptoms, ranging from mild to life-threatening.
  • Common allergens include nuts, shellfish, dairy, eggs, wheat, and soy.
  • Management involves strict avoidance of allergens, early recognition of symptoms, and prompt treatment.

Causes of Food Allergy

  1. Immune System Reaction
    • The immune system mistakenly identifies certain proteins in food as harmful, triggering an allergic response.
  2. Genetic Factors
    • Family history of allergies increases risk.
  3. Common Allergens
    • Tree Nuts: Almonds, walnuts, pecans.
    • Peanuts: Legumes but act as allergens.
    • Shellfish: Shrimp, crab, lobster.
    • Dairy Products: Cow’s milk and derivatives.
    • Eggs: Especially egg whites.
    • Wheat and Soy: Common in children, often outgrown.

Symptoms of Food Allergy

  1. Mild Symptoms
    • Skin reactions: Hives, redness, or itching.
    • Gastrointestinal discomfort: Nausea, vomiting, diarrhea, or abdominal pain.
    • Nasal symptoms: Sneezing, runny nose, or nasal congestion.
  2. Moderate Symptoms
    • Swelling of lips, tongue, or face.
    • Coughing, wheezing, or difficulty breathing.
  3. Severe Symptoms (Anaphylaxis)
    • Rapid pulse, drop in blood pressure, or dizziness.
    • Tightness in the throat or airway obstruction.
    • Loss of consciousness.

Complications of Food Allergy

  • Anaphylaxis: A life-threatening allergic reaction requiring immediate medical attention.
  • Growth Impairment: In children, due to restricted diets and malnutrition.
  • Social and Emotional Impact: Anxiety about accidental exposure.

Diagnosis of Food Allergy

  1. Medical History
    • Detailed review of symptoms, timing, and suspected foods.
  2. Skin Prick Test (SPT)
    • Small amounts of allergens are introduced into the skin to observe for reactions.
  3. Blood Tests
    • Measures IgE antibodies specific to certain allergens.
  4. Oral Food Challenge
    • Controlled ingestion of suspected allergen under medical supervision.
  5. Elimination Diet
    • Gradual removal and reintroduction of specific foods to identify triggers.

Treatment Options for Food Allergy

1. Immediate Treatment for Allergic Reactions

MedicationBrand NameManufacturerCost Range
Epinephrine Auto-InjectorsEpiPen, Auvi-QMylan, Kaléo$300–$600 per twin pack
AntihistaminesBenadryl, ZyrtecJohnson & Johnson, GSK$10–$20 per bottle
BronchodilatorsVentolin, ProAirGSK, Teva$30–$50 per inhaler
  • Epinephrine is the first-line treatment for anaphylaxis. Always carry an auto-injector if prescribed.
  • Antihistamines and bronchodilators manage mild to moderate symptoms but are not substitutes for epinephrine in severe reactions.

2. Long-Term Management

  • Avoidance of Allergen
    • Read food labels carefully for hidden allergens.
    • Educate caregivers, teachers, and friends about allergy management.
  • Oral Immunotherapy (OIT)
    • Gradual exposure to small amounts of the allergen under medical supervision to build tolerance.
  • Desensitization Therapy
    • Involves controlled allergen exposure to reduce severity of reactions over time.

3. Dietary Support

  • Substitute Foods
    • Dairy alternatives: Almond, soy, or oat milk.
    • Gluten-free products for wheat allergy.
  • Nutritional Counseling
    • Ensures balanced nutrition, especially in children.

Monitoring Parameters

  • Track frequency and severity of allergic reactions.
  • Ensure epinephrine auto-injectors are always accessible and unexpired.
  • Regular follow-ups with an allergist to reassess triggers and treatment.

Patient Counseling Points

  • Educate on early recognition of symptoms, especially anaphylaxis.
  • Demonstrate proper use of epinephrine auto-injectors.
  • Discuss cross-reactivity (e.g., peanuts and tree nuts).
  • Encourage wearing medical alert bracelets for severe allergies.
  • Stress the importance of avoiding allergens, even in trace amounts.

Use in Children

  • Ensure caregivers and schools are trained to manage allergic reactions.

Use in Pregnancy

  • Food allergies may persist, but management remains similar; epinephrine is safe for use in anaphylaxis.

Use in Elderly

  • Monitor for delayed reactions or interactions with other medications.

FAQs About Food Allergy

Q1: What causes food allergies?

  • Overreaction of the immune system to specific proteins in foods.

Q2: Can food allergies be cured?

  • No, but symptoms can be managed; immunotherapy may reduce severity.

Q3: What is anaphylaxis?

  • A severe, life-threatening allergic reaction requiring immediate epinephrine administration.

Q4: How are food allergies diagnosed?

  • Through history, skin prick tests, blood tests, or oral food challenges.

Q5: Are food allergies hereditary?

  • Yes, a family history of allergies increases risk.

Q6: Can children outgrow food allergies?

  • Yes, especially to milk, eggs, and soy. Peanut and tree nut allergies are less commonly outgrown.

Q7: What foods should I avoid with a peanut allergy?

  • Peanuts and foods with hidden peanut ingredients like sauces or desserts.

Q8: How can cross-contamination be avoided?

  • Use separate utensils and cooking equipment for allergen-free foods.

Q9: Is it safe to eat processed foods with food allergies?

  • Only if labels confirm no allergen presence or contamination.

Q10: Can stress worsen food allergies?

  • Stress does not cause allergies but may exacerbate reactions.

Q11: Is lactose intolerance a food allergy?

  • No, it is a digestive issue, not an immune response.

Q12: Can I reintroduce allergens into my diet?

  • Only under medical supervision, such as during an oral food challenge.

Q13: How do I store epinephrine auto-injectors?

  • Keep at room temperature and replace before expiration.

Q14: Can food allergies develop later in life?

  • Yes, adult-onset allergies can occur.

Q15: Are all reactions immediate?

  • Most are immediate, but some (e.g., alpha-gal syndrome) have delayed onset.