Food Allergy and Intolerance

Question 1

inappropriate immunologic response to antigens in food

Answer 1

immediate (IgE) Food Allergy

Question 2

prevalence of Food Allergy

Answer 2

10-11% of the US population

Question 3

onset of food allergy

Answer 3

any age, usually in childhood
15% manifest for the first time as adults

Question 4

risk factors for food allergy

Answer 4

Comorbid atopy
eczema
asthma
allergic rhinitis
other allergic disorders

Question 5

food allergy is an inappropriate activation of the immune system, mediated by what immunoglobulin

Answer 5

IgE

Question 6

manifestations of food allergy

Answer 6

1. present after even a tiny exposure to the allergen (ingestion, topical, inhaled)
   - very rapid onset - mins-hrs (< 2 hours)
2. Unpredictable - may vary from one exposure to the next
3. Severity - ranges from relatively mild to extremely severe or life-threatening

Question 7

associated with problems digesting or metabolizing food

Answer 7

Food Intolerance

Question 8

prevalence of Food Intolerance

Answer 8

15-20% of the US population, if not more

Question 9

onset of Food Intolerance

Answer 9

at any age, including adulthood

Question 10

risk factors of food intolerance

Answer 10

Often have functional gastrointestinal disorders (IBS, functional dyspepsia, others)

Question 11

food intolerance - if Ig present, more likely to be ___

Answer 11

non-IgE, including IgG

Question 12

manifestations of food intolerance

Answer 12

1. Usually present after exposure to the food, with severity correlating with dose of food ingested
   - manifest up to 72 hr after exposure
2. Symptoms focus around the GI tract
3. Typically predictable - similar presentations each time, depending on dose of food
4. Severity - may be uncomfortable, but usually not life-threatening

Question 13

most common problem foods for food allergies

Answer 13

usually proteins
Typically no difference in varieties that are organic, not treated with antibiotics

Question 14

MC allergenic foods in the US

Answer 14

Peanuts, tree nuts, and fish/shellfish
Other common allergens - wheat, eggs, milk, soybeans, sesame

Question 15

Over ___ possible food and additive allergens

Answer 15

160

Question 16

some common food intolerances

Answer 16

problem foods vary widely
1. Lactose, fructose, gluten, caffeine
2. General carbohydrate intolerance - usually secondary to high-FODMAP foods

Question 17

9 most common allergens must be listed on food labels if present

Answer 17

Peanuts, tree nuts, fish, shellfish, wheat, eggs, milk, soybeans, sesame

Question 18

what is Not required to identify if product is at risk for environmental contamination

Answer 18

food labels

Question 19

what were the old guidelines (pre-2008) of allergen exposure.

Answer 19

• avoid exposure to allergens in early life
• Based off theory that due to low secretory IgA in infants, less antigen would be bound (more absorbed) and therefore could trigger a greater immunogenic response

Question 20

what are the newer guidelines of allergen exposure

Answer 20

no convincing evidence to delay allergen exposure
1. Data suggested delayed exposure actually might increase risk of food allergy
2. May consider delaying/avoiding in select children with high risk for food allergy
- Family history of food allergy
- Strong presence of atopic/allergic disorders
- May also consider hypoallergenic infant formulas, modifying mother’s diet

Question 21

ways for childhood allergen exposure

Answer 21

1. early indirect exposure
   - Having mother eat allergenic foods while pregnant
   - Consuming allergenic foods while breastfeeding
2. Introduction of allergens for direct consumption
   - Foods made with allergens
   - Mix-in liquids or powders

Question 22

presentation of immediate (IgE) food allergy

Answer 22

present from a few minutes to a few hours (usually 2 or less) after exposure to the allergenic food
- Derm - pruritus, flushing, urticaria/angioedema, diaphoresis
- Eyes - conjunctival injection, lacrimation, periorbital edema, pruritus
- Nose - sneezing, rhinorrhea, nasal congestion
- Mouth - oral pruritus, metallic taste
- Upper Airway - hoarseness, stridor, sense of choking, laryngeal edema
- Lower Airway - dyspnea, tachypnea, wheezing, cough, cyanosis
- CV - tachycardia, bradycardia (if severe), arrhythmias, hypotension, cardiac arrest
- GI - N/V/D, abdominal cramping, bloating
- Neuro - sense of impending doom, panic, syncope, dizziness, seizures

Question 23

clinical presentation common in children for food intolerences

Answer 23

trend towards cutaneous and GI symptoms

Question 24

clinical presentation common in adults in Immediate (IgE) Food Allergy

Answer 24

trend towards respiratory and CV symptoms

Question 25

management for acute food allergy

Answer 25

limiting inflammatory response 1. Administration of EPI ASAP 2. Additional therapeutics - steroids, antihistamines, beta-agonists, other supportive care

Question 26

management for chronic food allergy

Answer 26

focus on avoiding allergenic food exposures

Question 27

Oral Allergy Syndrome aka ___

Answer 27

Pollen-Allergy Food Syndrome

Question 28

what is the MC form of food allergy in adults

Answer 28

Oral Allergy Syndrome Allergens in some foods have similar molecular structure to allergenic pollen proteins These allergens are heat-labile and acid-labile Much milder presentation overall

Question 29

pts with Oral Allergy Syndrome usually report a hx of ?

Answer 29

seasonal allergies, pollen sensitivity Initial sensitization is typically to pollen, and patients then experience IgE-mediated cross-reactivity

Question 30

Localized, mild immune (IgE) response

Answer 30

Oral Allergy Syndrome

Question 31

s/s of Oral Allergy Syndrome

Answer 31

1. present usually within a few minutes after exposure to the allergenic food - Mouth - oral pruritus, swelling of oral structures - Upper Airway - hoarseness, laryngeal edema, mild stridor or sense of airway narrowing

Question 32

Oral Allergy Syndrome usually presents after exposure to what?

Answer 32

raw fruits and vegetables Do not have symptoms with same foods if cooked

Question 33

management for Oral Allergy Syndrome

Answer 33

1. Acute Management - usually self-limiting - Antihistamines - Monitor 2. Chronic Management - avoiding allergenic foods - Antihistamines and other methods to control underlying allergic condition - Eating cooked versions of foods 3. May for work-up of more serious allergic disorder if… - Symptoms are present after tree nut or peanut exposure - Systemic symptoms are present

Question 34

disorder characterized by inability to digest lactose, a milk sugar, due to deficiency of the enzyme lactase

Answer 34

Lactose Intolerance

Question 35

what tolerance is actually considered normal for adult mammals

Answer 35

Lactose Intolerance

Question 36

what is the Most common enzyme deficiency - >50% of adults worldwide are deficient

Answer 36

Lactose Intolerance

Question 37

at what age does natural levels of lactase often decline

Answer 37

5 y/o

Question 38

what is the ethnic ties with lactose intolerance

Answer 38

Northern European descent - most likely to tolerate lactose well African, Asian, Mediterranean, Native American - most likely to have lactase deficiency

Question 39

s/s of Lactose Intolerance

Answer 39

1. GI - abdominal pain, bloating, flatulence, borborygmi, nausea, diarrhea hours-days after ingestion of lactose-containing food or beverage - abd pain - cramp-like, localized to periumbilical area or RLQ/LLQ - Children - more likely to have predominant diarrhea; may see bulky, frothy, watery stool 2. Severity of symptoms varies depending on amount of lactose consumed, presence of other GI comorbidities, patient sensitivity to symptoms

Question 40

how to diagnose Lactose Intolerance

Answer 40

1. clinically; can trial a lactose-free diet to see if symptoms improve - Stool Studies - increased stool osmotic gap and decreased stool pH due to undigested lactose that becomes fermented by gut bacteria - Hydrogen Breath Test - patient consumes solution containing lactose and serial breath samples are measured for hydrogen content - Small Bowel Biopsy - can be performed during endoscopy to measure presence of lactase enzyme

Question 41

tx for lactose intolerance

Answer 41

focuses on minimization of lactose in diet 1. Dietary Lactose Restriction - equivalent of 2 cups of milk/day or less - Increasing numbers of products with less lactose content 2. Calcium / Vitamin D Supplementation - To avoid nutritional deficiency 3. Lactase Enzyme Supplementation - may try, but variable results

Question 42

protein found in many cereal grains Wheat, rye, barley, triticale, malt, brewer’s yeast, wheat products (spelt, semolina, farina, etc.)

Answer 42

gluten

Question 43

Non-Celiac Gluten Intolerance is how common? (%)

Answer 43

13%

Question 44

Gluten-Sensitive Enteropathy (Celiac Disease) is how common?

Answer 44

1% of US

Question 45

what intolerance Historically found predominantly in patients of European descent Increasing prevalence in multiple ethnic and racial groups North Africa, Middle East, India, Northern China

Answer 45

gluten intolerance

Question 46

s/s of gluten intolerance and celiac disease

Answer 46

1. GI - abd pain, bloating, flatulence, borborygmi, nausea, diarrhea hrs-days after ingestion - Diarrhea - bulky, foul-smelling, floating stools due to steatorrhea - Malabsorption - wt loss, anemia, nutritional deficiencies (B vitamins, D, calcium) --- MC with Celiac Disease 2. Oral - atrophic glossitis, angular cheilitis 3. Skin - itchy papules (dermatitis herpetiformis) 4. Neuro - headache, peripheral neuropathy, epilepsy 5. Psych - depression, anxiety 6. Heme - iron deficiency anemia, hyposplenism 7. MSK - osteomalacia, osteopenia, increased fracture risk

Question 47

how to diagnose Gluten Intolerance and Celiac Disease

Answer 47

can trial gluten-free diet to see if symptoms improve 1. Gluten Intolerance - dx of exclusion (no + serum or biopsy tests) 2. Serum Antibody Assay - serum antibody panel may be positive in patients with celiac disease - advised to keep gluten in diet until panel is performed 3. Small Bowel Biopsy - can be performed during endoscopy to demonstrate atrophy of intestinal mucosa in patients with celiac disease

Question 48

tx for Gluten Intolerance and Celiac Disease

Answer 48

1. Dietary Counseling - Consider dietician consult or social services - Re-challenge with gluten not recommended 2. Repeat Testing - Monitor serum celiac-related antibodies for response to therapy - Controversial as to whether repeat small bowel biopsy - Atrophy of intestine does tend to improve the longer a patient avoids gluten 3. Supportive Care - pneumococcal vaccination, repletion of nutritional deficiencies 4. Gluten Enzyme Supplementation - may try, but variable results - Not widely recommended, esp with celiac disease focuses on elimination of gluten from the diet