Otolaryngology Book

http://www.fpnotebook.com/

Food Allergy

Advertisement

  1. See Also
    1. Anaphylaxis
  2. Causes
    1. Common Childhood Food Allergies
      1. Cow's Milk Allergy
      2. Egg Whites
      3. Wheat
      4. Soy
    2. Food Allergies associated with Anaphylaxis
      1. Nuts (allergy often seen in Atopic Patients)
        1. Peanuts (legume)
        2. Tree nuts
          1. Pistachios
          2. Walnuts
          3. Cashews
          4. Almonds (and marzipan)
          5. Hazelnuts or filberts
          6. Macadamian Nuts
          7. Pecans
          8. Brazil nuts
          9. Pine nuts
      2. Fish
      3. Shellfish
        1. Crab, crayfish, prawns, shrimp, lobster
      4. Seeds
        1. Sesame, Caraway
  3. Pathophysiology
    1. Initial reaction (Sensitization)
      1. IgE antibodies produced to food
    2. Subsequent Reaction
      1. IgE fixed to Mast Cells in Skin, GI, Respiratory
      2. Reacts to allergen
      3. Releases
        1. Histamine
        2. Chemotactics attract Eosinophils
        3. Prostaglandins and leukotrienes are released
  4. Symptoms
    1. Skin
      1. Urticaria (Hives)
      2. Atopic Dermatitis
    2. Respiratory
      1. Allergic Rhinitis
      2. Asthma
    3. Gastrointestinal
      1. Vomiting
      2. Blood in stool
      3. Diarrhea
    4. Anaphylaxis
  5. Differential Diagnosis: Postprandial collapse
    1. Airway Foreign Body
    2. Non-allergic food reaction
      1. Monosodium glutamate
      2. Sulfite
      3. Scombroid Fish Poisoning
  6. Diagnosis
    1. Immediate Reacting IgE skin Test
      1. Epicutaneous stick with Fresh Food Extract
      2. Sensitive and Specific
      3. Do NOT perform for food suspected of Anaphylaxis
    2. In-Vitro test for allergen-specific IgE Antibodies
      1. Less sensitive than skin test
      2. Safe alternative to skin test (Anaphylaxis suspected)
    3. Open Food Challenge
      1. Use for reintroduction of foods after 2-3 years
        1. For foods with less serious reactions
          1. Example: Hives to milk or eggs
      2. Diet diaries
      3. Short-term Elimination Diets
  7. Management: Milk Allergy or intolerance with GI Symptoms
    1. Differentiate from Infantile Colic
      1. Colic will resolve spontaneously after 3-4 months
      2. Milk substitution is unnecessary
    2. Substitute Casein Hydrolysate (Cow's Milk) Formula
      1. Nutramigen, Pregestimil, Alimentum
      2. Soy-based formula is not appropriate substitution
  8. Management: Anaphylaxis reaction history
    1. Indefinitely avoid causative food
    2. Epinephrine Self-Injectors for home/school
      1. Child over age 6
        1. Epinephrine (1:1000) 0.3 mg SQ (EpiPen)
      2. Child under age 6
        1. Epinephrine (1:2000) 0.15 mg SQ (Epi-Pen Jr)
  9. Management: Reintroduction of prior food allergies
    1. Mix with other foods
      1. Eggs in baked products (instead of scrambled eggs)
      2. Milk in Cheese or yogurt (instead of glass of milk)
    2. Do not reintroduce foods with previous Anaphylaxis
  10. Management: Specific food Issues
    1. Egg Allergy and MMR and flu Vaccination
      1. MMR and flu vaccines contain minute egg amounts
      2. If tolerates egg containing foods
        1. MMR and Influenza Vaccine ok
      3. If unsure:
        1. Skin test
        2. Monitor for 2 hours after vaccination
    2. Fish Allergy
      1. Avoid fresh and saltwater fish
      2. Most fish-allergic pts can tolerate canned tuna
    3. Nut allergy (often associated with Anaphylaxis)
      1. Do not eat at buffets
      2. Avoid unlabeled candies and desserts
      3. Avoid ice cream parlors
  11. Associated Conditions: Conditions NOT associated with Food allergy
    1. Abnormal Child Behavior
      1. Myths:
        1. Hyperactivity, Insomnia, Anxiety (Shannon,1922)
        2. "Allergic Attention Fatigue Syndrome" (Rowe, 1950)
      2. Reality
        1. No proven relationships
    2. Attention-Deficit Disorder (ADD)
      1. Myth: Attention Deficit Disorder related to dietary additives
        1. Dietary Salicylates
        2. Artificial food colors and flavors
          1. Feingold, 1975
      2. Reality
        1. Only 2% ADD Children would benefit from diet change
      3. Reference
        1. Lipton (1983) J Am Diet Assoc 83:132
    3. Sugar "Allergy"
      1. Myth: Refined sugars aggravate behavioral problems
        1. Suggested to provoke hyperactivity, aggressive, inappropriate behavior
      2. Reality
        1. Sugar does not increase activity
          1. Milich (1986) Clin Psychol Rev 6:493
          2. Mahan (1988) Ann Allergy 61:453
        2. Sucrose has "calming effect" when c/w Aspartame
          1. Kruesi (1986) Annu Rev Nutr 6:113
          2. Bachorowski (1990) Pediatrics 86:244
  12. Prognosis
    1. Transient Food Allergies
      1. Most food allergies last only a few years
      2. Milk, eggs, wheat or soy allergies usually resolve
    2. Lifelong Food allergies
      1. Foods associated with systemic Anaphylaxis
      2. Nuts, fish, seeds allergies persist
  13. References
    1. Anderson (1997) Am Fam Physician 56(5):1365
    2. Sampson (2002) N Engl J Med 346:1294

Navigation Tree