⚡ What is Food Allergy?
- An overreaction of the immune system to a food protein.
- Most often IgE-mediated, but non-IgE forms also exist.
- Most common allergens:
- In children: milk, egg, soy, wheat, peanut, tree nuts, fish, shellfish
- In adults: shellfish, fish, peanut, tree nuts
🧪 Types & Symptoms
1. IgE-mediated (immediate reactions):
- Itching, swelling, hives
- Breathing difficulty, wheezing, cough
- Vomiting, diarrhea, stomach pain
- Anaphylaxis: life-threatening!
2. OAS / PFAS (oral allergy syndrome):
- Itchy mouth/throat after raw fruit/vegetable intake
- Linked to pollen allergies (cross-reaction)
3. FPIES (non-IgE):
- In infants: vomiting, diarrhea, dehydration
4. Milk protein-induced proctocolitis:
- Bloody/mucousy stool, poor weight gain
5. Eosinophilic GI disorders:
- Depends on location: reflux, food impaction, vomiting, weight loss
🔍 Diagnosis
- History: food type, preparation, reaction time and severity
- Physical exam: skin, lungs, circulation, nutrition
- Tests:
- Specific IgE (blood or skin prick test)
- Component-resolved diagnostics (e.g., peanut proteins)
- Tryptase after anaphylaxis
- Elimination diet, oral food challenge (gold standard, but risky)
🛡️ Treatment & Prevention
✅ Only proven treatment: complete avoidance of allergen
- Reading labels, avoiding cross-contact (utensils, oil)
- Watch for hidden sources (medications, cosmetics)
- Know potential cross-reactions (e.g., cow ↔ goat milk)
🧯 Emergency plan:
- Epinephrine auto-injector (must be available at all times)
- Written emergency plan (for school, daycare, etc.)
- Wear medical alert ID
- Educate family, school staff
💊 Medications:
- Epinephrine: first-line for anaphylaxis
- Antihistamines, steroids, bronchodilators: adjunct only
💉 Newer therapies:
- Omalizumab: raises threshold for allergic reactions to multiple foods
- Oral Immunotherapy (OIT): especially for peanut; effective but may cause reactions
🧠 Mental health:
- Support for anxiety, bullying
- Family and patient education
