Peds Allergies Flashcards
Food Allergies:
-may or may not be mediated by which immunoglobulins?
IgE mediated and non-IgE mediated
Characteristics of IgE mediated rxns?
Non-IgE mediated rxn characteristics?
IgE mediated
- rapid onset
- skin
- GI tract
- Resp Tract
- Anaphylaxis*
NON-IgE:
- occur hours to days after exposure
- usually present in infants
- present as chronic skkin conditions or GI sx;
- -proctitis
- -enteropathy
- -enterocolitis
*Think contact dermatitis, rxn to lotions, irritation or inflammation of the GI.
90% of IgE mediated rxns in children are from what 8 sources? Which of these 8 are lifelong and which resolve by age 5?
- cows milk
- eggs
- soybean
- wheat
- peanuts
- tree nuts
- fish
- shellfish
Lifelong:
- peanuts
- tree nuts
- fish
- shellfish
Resolve by age 5:
- cows milk
- eggs
- soybean
- wheat
Sx of Food induced allergic rxns (IgE and non-IgE)
- cutaneous
- ocular
- upper resp
- lower resp
- GI oral
- lower GI
- CV
- cutaneous: erythema, pruritis, urticaria, angioedema
- ocular: pruritus, conjunctival erythema, tearing, periorbital edema
- upper resp:nasal congestion, pruritus, rhinorrhea, sneezing, laryngeal edema, hoarseness, dry cough
- lower resp: cough, chest tightness, dyspnea, sneezing, intercostal retractions
- GI oral: angioedema of lips, tongue, or palate, oral puritus, tongue swelling
- lower GI: nausea, colicky abd pain, reflux, vomiting, diarrhea
- CV: tachycardia, hypotension, dizziness, fainting, LOC
Food Allergy Dx & Tx
Dx:
-Hx!!!!! if lab test isnt consistent with hx then its not an allergy. (eg if test shows allergy to cows milk but pt can tolerate cows milk you have them continue to drink cows milk)
- PE
- Skin prick test
- Allergen specific IgE (serum test)*
- oral food challenge
Tx:
- avoidance
- Epi-pen for tx of anaphylaxis
MC associated sx w/ food allergies
-atopic dermatitis(eczema), acute urticaria.
Nasopharyngeal sx associated with food allergy?
-acute rhinitis NOT chronic rhinitis
Skin prick allergy testing
- what is a positive result?
- describe specificity and sensitivity of this test?
- be sure to discontinue what medications prior to this test?
Positive result: wheal at least 3mm greater than the negative control.
- 95% sensitive, 50% specific…so, better at ruling out allergy than ruling in; many false positives.
- Antihistamines should be discontinued prior to testing.
What is serum IgE testing? What is needed to make dx?
-Serum IgE testing is a blood test that detects IgE to specific allergens. There are cut off values that aid in determining if the pt is actually allergic.
Need to make sure pt has clinical hx of food allergy to confirm dx.
Gold Standard for dx of food allergy?
oral food challenge is gold standard for dx of food allergy.
What is oral food challenge?
What is atopy patch test? When do we use this?
pt is given gradually increasing amounts of suspected food allergen over a period of time of hours to a day. Requires close medical supervision
Atopy Patch Test: used to dx delayed hypersensitivity T-cell mediated rxn such as contact dermatitis.
-this is not recommended for IgE food allergies.
Does the level of serum specific IgE or the size of wheal response determine the severity of an allergy?
No.
T/F, if consuming food without experiencing a clinical rx, SPT, and IgE testing is not warranted?
T/F, for whatever reason testing is conducted and a positive results is observed, it is important to stress to the caregiver that the food continue to be consumed on a regular basis. Why or why not?
True, and true.
What: testing indicates that the child is sensitized to allergen, a prolonged absence of the food from the diet could lead to clinical sx upon re-exposure.
Pollen-Food Allergy Syndrome
- aka
- what is this?
- sx
aka: oral allergy syndrome
what: IgE mediated rxn that affects the oropharynx, thought to occur from cross-reactivity between proteins present in pollens anad those expressed by fruits and veggies
sx:
- tingling & itching of lips, tongue, and palate
* sx do not occur when fruit or veggie is cooked or microwaved.
What fruits are associated with each allergy:
- birch pollen allergy cross reactivity
- ragweed pollen cross reactivity
- grass pollen cross reactivity
Birch:
-apples, plums, peaches, nectarines, cherries, and almonds.
Ragweed:
-melons, bananas, and tomatoes
Grass: melons and kiwi
