Food allergy series: Food related allergic disorders
There are many types of allergic diseases caused by food.
Oral allergy syndrome:
- IgE reaction.
- Causes itching and swelling in the mouth and sometimes the throat.
- Less than 2% of cases progress to anaphylaxis.
- Your body mistakes certain raw fruits and vegetables for pollens and reacts.
- Cooked foods are usually safe in patients with OAS to raw foods.
Asthma and rhinitis:
- IgE mediated.
- Caused by inhaling food protein.
- Most common in infants and children.
- Can affect adults in specific work environments, like bakeries.
- Most commonly induced by the eight major food allergens: egg, milk, wheat, soy, peanut, tree nuts, fish and shellfish.
Urticaria and angioedema:
- IgE mediated.
- From ingestion or skin contact.
- Food ingestion causes 20% of acute urticaria cases and 2% of chronic urticaria cases.
- More common in children.
- Usually due to eight major allergens.
GI hypersensitivity:
- IgE mediated.
- Immediate vomiting in response to major food allergens.
Food associated, exercise induced anaphylaxis:
- IgE mediated.
- Ingestion of food in close time proximity to exercising.
- Exercise may affect the way the GI tract absorbs and digests allergens.
- Wheat, shellfish and celery most common to provoke this reaction.
Delayed food-induced anaphylaxis to meat:
- IgE mediated.
- Occurs several hours after eating.
- Body makes antibodies to carbohydrate a-gal.
- A tick bite can cause the body to make these antibodies.
- Beef, pork and lamb cause reactions.
Atopic dermatitis:
- IgE and delated cell mediated reactions.
- 35% reactions in children due to food.
- May be due to food reactive T cells in the skin.
- Egg and milk most common.
- Usually resolves on its own.
Eosinophilic GI disease:
- IgE and delated cell mediated reactions.
- Due to eosinophil driven inflammation.
- Can cause difficult or painful swallowing, weight loss, obstruction and edema.
- Elimination diets are first line treatments.
- Endoscopy is diagnostic.
FPIES:
- Not due to IgE.
- Usually found in infants.
- Exposure to food proteins causes chronic vomiting, diarrhea, low energy and poor growth.
- Cow’s milk, soy, rice and oat are most common offending foods.
- Cells are more responsive to TNFa and less responsive to TGFb.
- Usually resolves with age.
Food protein induced allergic proctocolitis:
- Not due to IgE.
- Causes mucousy, bloody stools.
- In response to breast milk containing allergen.
- Treated by removing food from mother’s diet.
Heiner Syndrome:
- Not due to IgE.
- Occurs in infants.
- Triggered by milk, may be a milk specific IgG reaction.
- Causes pulmonary infiltration, upper respiratory symptoms, iron deficiency anemia and failure to thrive.
Celiac disease:
- Not due to IgE.
- Autoimmune disease causes malabsorption and enteropathy.
- Caused by reaction to gliadin, gluten protein.
- Can cause bone abnormalities, IgA deficiency, and other issues.
- Can present at any age.
- Is lifelong.
Allergic contact dermatitis:
- Not due to IgE.
- Eczema in response to metals in foods.
- Mostly adults.