Lecture 11: Food Allergies and Intolerance Flashcards
What is a food allergy?
Inappropriate immunologic response to antigens in food, specifically IgE.
When do most allergies appear?
Childhood
What is food intolerance?
Problems digesting or metabolizing food
What are the primary risk factors for food intolerance?
Functional GI disorders
* IBS
* Functional dyspepsia
* Others
Generally gets worse the more they eat
What are the shared symptoms between food allergies and intolerance?
- Nausea
- Diarrhea
- Vomiting
What are the most common allergens in the US?
- Peanuts
- Tree Nuts
- Fish/Shellfish
What foods/substances are people usually intolerant of?
- Lactose
- Fructose
- Gluten
- Caffeine
What is the US legal requirement when it comes to allergen listing? What is not required?
The 9 most common allergens must be on the food label if they are present.
However, not required to label if it is at risk of contamination.
What are the current guidelines in regards to early chilldhood allergen exposure?
DO not delay exposure.
Only select children may need delaying, such as strong family Hx or atopic disorders.
New guidelines came out in 2009.
What are the various ways children can be exposed to allergens?
- Mother eats allergenic foods while pregnant or breastfeeding.
- Foods mixed with allergens or powders.
What kind of IgE symptoms do children tend to have? Adults?
Children: Cutaneous and GI
Adults: Respiratory and CV
How do we treat suspected IgE food allergy mediated reactions?
Epinephrine is a MUST for acute management. It can result in a higher risk of death as it is delayed.
What is oral allergy syndrome?
Pollen-allergy food syndrome.
MC type of food allergy in adults.
How can we help someone eat pollen allergens?
They are heat and acid labile, so cooking them tends to alter the allergen.
What history suggests oral allergy syndrome?
- Seasonal allergies
- Pollen sensitivity
Describe the response of someone with oral allergy syndrome.
Localized, mild immune (IgE) response.
* Mouth: oral pruritis, swelling of oral structures
* Upper airway: hoarseness, laryngeal edema, mild stridor or sense of airway narrowing
When does an oral allergy response typically occur?
Eating raw fruits or vegetables, but no symptoms if they are cooked.
How do we manage oral allergy syndrome?
- Acute: Antihistamines
- Chronic: Avoid and antihistamines
What is the MC enzyme deficiency in the world?
Lactase deficiency
What country tends to have the least lactose intolerance?
Northern europeans
What tests can we run to check for lactose intolerance?
- Stool studies: increased osmotic gap, low pH
- Hydrogen breath test
- Small bowel biopsy: measure lactase enzyme
How do we treat lactose intolerance?
- Less than 2 cups of milk daily
- Calcium/Vit D supplementation
- Lactase enzyme supplement
What is gluten? What is the primary grain it is found in?
A protein found in grains, primarily wheat!
What are the two conditions associated with gluten?
Non-celiac gluten intolerance (13%)
Gluten-sensitive enteropathy (celiac disease)
What ethnicity generally has higher rates of gluten intolerance or celiac?
Europeans
What kind of diarrhea do gluten intolerance/celiac present with?
- Bulky
- Foul-smelling
- Floating/steatorrhea
What is unique about gluten intolerance/celiac?
Multi system manifestations.
- HA
- Seizures
- Depression
- Iron deficiency anemia
- Osteomalacia, osteopenia
What is the common rash seen in celiac/gluten intolerance?
Dermatitis Herpetiformis
How do we diagnose celiac or gluten intolerance?
- Gluten intolerance: dx of exclusion
- Serum antibody assay (for celiac, but advised to keep eating gluten until test is performed)
- Small bowel biopsy (atrophy of intestinal mucosa in celiac)
How do we treat gluten intolerance or celiac disease?
- Dietary counseling (Avoid gluten, do not rechallenge.)
- Repeat testing (monitor antibodies)
- Supportive care (Pneumococcal vaccine, nutritional supplements)
- Gluten enzyme supplementation (variable results, not recommended in celiac patients)
