Allergies Flashcards
what is ARF?
adverse reactions to food
___% of population alters diet cuz ARF
20
what are immunological reactions to food and reactions to food:
production of IgE, inflam. mediators released from eosinophils in GI, food protein enteropathies in milk or soy, associated diseases which has an immune component (celiac disease)
adverse rxn where body unable digest, absorb, or metabolize food or component of food (non immunological)
food intolerance
troublesome rxn after ingestion of food, unclear whether immunological or physiologic effect
food sensitivity
examples of cell mediated food allergies?
celiac, FPIES
etiology?
heredity, antigen exposure, maternal diet, early infant feeding, GI microbiota, , skin and gut, dysbiosis in microbiome, increased intestine permeability
most important cells in initiation of recognition process:
dendritic cells (intestinal mucosa)
70% of immune cells located in gut-associated ___ tissue
lymphoid
risk factors for allergy?
hygiene hypothesis, increased pollution, family hx, time of food intro
sensitization on first exposure involves ___ antibodies, in subsequent exposure involves ____ + ____
IgE; IgE, mast cells
what does IgE and mast cells cause release of?
histamine, prostaglandins, interleukin (mediators)
____ cells responsible for humoral and cell mediated immunity
B + (type 2 helper) T
b and t cells are types of ____
lymphocytes
what do Th1 do?
regulate B cells to produce antibodies and destroy antigens; triggers protective response to a pathogen; produce IgM, IgG, IgA
what do Th2 do?
mediate allergic response by regulating production of B cells of IgE-sensitized to food or other allergens, produce IgE
B cells become _____ which attach to ___ cells
plasma cells which produce antibodies; mast
IgE binds to mast cell, causing ____
degranulation (release inflammatory mediators)
allergy skin and mucous symptoms:
eczema, uticaria (hives), inflammation, itching
allergy digestive symptoms:
ab pain/bloating, nausea/vomiting, diarrhea, constipation
allergy resp symptoms:
itchy watery eyes, cough, rhinitis, throat tightening
allergy systemic symptoms:
anaphylaxis, hypotension, dysrhythmias
common pediatric allergens:
cow’s milk, egg, wheat, soy, peanut/treenuts
common adult allergens
peanut/treenuts, fish/shellfish, sesame
reliability/validity of skin tests depends on:
quality of testing material, experience of technician and interpretor
skin tests measure ____
wheal and flare
size of wheal and flare measured positive ____ to ___+
1; 3
diameter > ____mms to diagnose allergy
3
why false positives?
skin mast cells by stimuli don’t degranulate the mast cells in the digestive tract, gastric acid and digestive enzymes can degrade antigens, raw form in extract may be degraded during cooking
blood test for allergies:
RAST, an enzyme-linked immunosorbent assay with broader range sensitivity
example of unproven test:
allergen specific IgG measurement (cytotoxicity assays, applied kinesiology, hair analysis)
oral allergy syndrome is:
pollen-food allergy syndrome, rapid onset, confined to mouth, itchy/irritation, coexists with seasonal allergy, caused by raw fruit/nuts
____ means shared between foods and pollens
conserved homologous proteins
foods with birch pollinosis?
apples, carrots, celery, potatoes, hazelnuts
foods with ragweed pollinosis:
melons, bananas
brazil nut allergy:
cherries, apricots, plums, peaches
what is food elimination?
eliminate all forms of suspected food, gradually introduce foods back to diet
what is food challenge?
one food at a time on diff days; be prepared for emergency treatment of rxns
repeated exposure to latex can cause ______
cross-reactivity between latex and some foods (chestnut, kiwi, fig, apple, apricot, cherry, banana, avocado, pear)
human milk is protective against ____ disease
atopic
if allergic to cows milk protein , need use _____ formulas
protein hydrosylate
rare and characterized by food-related rxn (GI symptoms), treatment is with prednisone
eosinophilic gastroenteritis (diff from food allergy cuz lack of specific offending food)
acute, systemic, severe, potentially fatal allergic rxn
anaphylaxis
in anaphylaxis, the inflammatory mediators cause:
systemic vasodilations of BV, causing sudden severe dip of BP; lungs have edema of mucosa and constriction of bronchioles, obstructing airways
anaphylaxis is ____ rxn
biphasic
treatment of anaphylaxis:
self injectable epinephrine, antihistamines, hospital O2 and IV fluids to stabilize
exercise induced anaphylaxis has these symptoms:
hives, itching, SOB, low BP
why does exercise induced anaphylaxis occur?
cuz exercise triggers the potential for release of histamine and other mediators from mast cells
foods involved in exercise-induced anaphylaxis:
wheat, celery, shellfish, chicken, peaches, nuts
presents with severe vomiting, lethargy, possible hypotension or cyanosis, triggered by milk, soy, rice, oats
food protein-induced enterocolitis
presents with bloody stools in otherwise healthy infant, occurs in breastfed infants, related to mom ingesting cow’s milk
food protein-induced proctocolitis
allergen immunotherapy with limited evidence:
oral immunotherapy (developing tolerance, desensitization)
