Allergies Flashcards
1
Q
What percent of kids are affected by food allergies? What type of mediated rxns?
A
- 6-8%
- IgE (anaphylaxis) or non-IgE mediated rxns
2
Q
IgE mediated rxns characteristics?
A
- typically rapid in onset (occur w/in minutes)
- skin
- GI tract
- respiratory tract
- anaphylaxis
3
Q
8 most common sources of IgE mediated rxns (90%)
A
- cows milk
- eggs
- soybean
- wheat
- peanuts
- tree nuts
- fish
- shellfish
4
Q
Which of the 8 most common sources of IgE mediated rxns usually (80%) resolve by age 5?
A
- cow’s milk
- eggs
- soybean
- wheat
5
Q
Which of these common sources of allergies are usually lifelong?
A
- peanuts
- tree nuts
- fish
- shellfish
6
Q
Characteristics of a non-IgE mediated rxn?
A
- occurs hours to days after exposure
- typically in infants
- can present as chronic skin conditions or most commonly manifests as GI sxs:
proctitis/proctocolitis
enteropathy
enterocolitis
7
Q
Sxs of food induced allergic rxn (IgE and non-IgE mediated)?
A
- cutaneous: erythema, pruritus, urticaria, angioedema
- ocular: pruritus, conjunctival erythema, tearing, periorbital edema
- upper respiratory: nasal congestion, pruritus, rhinorrhea, sneezing, laryngeal edema, hoarseness, dry cough
- lower respiratory: cough, chest tightness, dyspnea, wheezing, intercostal retractions
- GI oral: angioedema of lips, tongue, or palate, oral pruritus, tongue swelling
- lower GI: nausea, colicky abd pain, reflux, vomiting, diarrhea
- CV: tachycardia (occasionally bradbradia cardia in anaphylaxis), hypotension, dizziness, fainting, LOC
8
Q
Dx of food induced allergies?
A
- Hx
- physical
- skin prick test, allergen specific serum IgE, oral food challenge
- pts with large wheals from skin prick test or with high serum specific IgE are likely to have food allergy
- parent and pt reports of food allergy should be confirmed with testing as mult studies demonstrate 50-90% of presumed food allergies are not allergies
9
Q
Tx of food induced allergies?
A
- avoidance
- epi-pen for tx for anaphylaxis
10
Q
What sxs can be assoc with food allergies?
A
- atopic dermatitis
- acute urticaria
11
Q
Relationship b/t atopic dermatitis (eczema) and food allergies?
A
- food allergy has been reported in up to 35% of pts referred to an allergist or derm for atopic dermatitis
- consider eval in infants and children with moderate to severe atopic dermatitis or if there is a hx of exacerbation when eating specific foods
- if food allergy is dx, the atopic dermatitis often improves after dietary elimination of that food
12
Q
Relationship b/t acute and chronic urticaria with food allergies?
A
- the causes of acute urticaria vary and include infection, drug rxn, and food allergy
- acute urticaria is common sx present with food allergy
- in contrast, chronic urticaria is rarely related to food allergy
- food allergy testing is rarely indicated for chronic urticaria since most cases are idiopathic
13
Q
What nasopharyngeal sxs occur with food allergies?
A
- acute rhinitis (typically assoc with other orpharyngeal sxs such as pruritus of throat and angioedema)
- chronic rhinitis is NOT a manifestation of food allergy
14
Q
Most appropriate test in initial assessment of food allergy? Test results?
A
- serum specific IgE testing or skin prick testing
- a positive rxn is a wheal at least 3 mm greater than negative control
- neg predictive value is greater than 95% while the positive predictive value is less than 50%, therefore there are many false positive results
- antihistamines should be d/c prior to testing
- testing can’t be performed on skin with extensive eczema/rash or in pts with dermatographia
15
Q
What is impt to remember about serum specific IgE testing?
A
- detection of serum IgE to specific allergens
- all positive and neg tests (skin and serum tests) need to be correlated with pts clinical hx
- a + test alone doesn’t make the dx of clinical food allergy (evidence of sensitization: immunological response)
16
Q
Gold std for dx of food allergy?
A
- a double blind, placebo controlled food challenge. Open challenges are generally used in most clinical settings
- pts may benefit from oral food challenge if they have borderline test results or if false + or - is suspected based on clinical hx
- may prevent unjustified food elimination from diet
17
Q
Oral food challenge process?
A
- pt given gradually increasing amt of suspected food allergen over a time period of hours to a day
- process requires close medical supervision
18
Q
Atopy patch tests use?
A
- currently used to d delayed hypersensitivity T cell mediated rxns such as contact dermatitis
- atopy patch testing for IgE mediated food allergy isn’t recommended
19
Q
What are variables in the skin tests and specific IgE tests?
A
- each allergen may have diff normal IgE level and wheal diameter
- also dependent on age of child
- cutoff value is the concentration of specific IgE for particular food allergen that is 90% predictive of clinical rxn to food
- increasing levels of specific IgE and wheal response to SPT correlate with allergy but don’t predict severity of rxn
20
Q
Why should food be continued on a regular basis if positive IgE results with no rxn while consuming food?
A
- because testing indicates that the child is sensitized to the allergen, a prolonged absence of the food from the diet could lead to clinical sxs upon re-exposure
21
Q
Tx of food allergies?
A
- children should be instructed not to share or trade food with others and to notify adults if they eat something that may contain the food to which they are allergic
- epi-pen auto injector (should be given IM in thigh) 0.15 mg of 1:1000 epi for 15-30 kg (33-66 lbs), and 0.3 mg of 1:1000 epi for anyone over 30 kg
22
Q
What is pollen-food allergy syndrome (PFAS) or oral allergy syndrome?
A
- IgE-mediated rxn that affects oropharynx
- occur from cross-reactivity b/t proteins present in pollens and those in fruits and veggies
- pts develop tingling and itching of lips, tongue, and palate when eating certain raw fruits and veggies
- systemic signs are very rate
- sxs don’t occur when fruit or veggie is cooked
- syndrome affects up to 50% of adults with allergic rhinitis secondary to pollens
23
Q
What fruits and veggies have a x-reactivity with birch pollen allergy?
A
- apples, plums, peaches, nectarines, cherries, almonds
24
Q
What fruits have a x-reactivity with ragweed pollen?
A
- melons, bananas, and tomatoes
25
What fruits have a x-reactivity with grass pollen allergy?
- melons and kiwi fruit
26
How do you dx PFAS?
- confirmed through skin prick testing to fresh foods and pollen and also with oral food challenges
- oral challenges are rarely necessary
27
Tx of PFAS?
- sxs can sometimes be controlled with antihistamines
- pts should avoid consumption of raw food product that produced sxs: may continue to eat specific food if it is cooked
- any pt who has hx of systemic sxs should strictly avoid the foods in all forms and carry an epi auto-injector
28
Who is more at a higher risk for fatal food-induced anaphylaxis? young kids or teens?
- teens
- dose provoking sxs in peanut-allergic pts decreases with age, which may in part contribute to the difference in risk
- studies have shown that adolescents have poor understanding of when food allergy rxns are severe and wehn epi is indicated
29
How common is accidental exposure to peanuts and tree nuts?
- high as 48%
| - 54% of adolescents admit to purposefully eating potentially unsafe food
30
Which food allergy is more common in adults than children?
- shellfish
31
Most common food allergies in children?
- milk
- egg
- peanut (second most common food allergy in adults but is still more common in children - affects 0.8% of young kids - 0-5 yrs)
32
Most common food allergies in adults?
- shellfish
- peanut
- tree nut
- allergies to tree nuts and fruits are more prevalent among adolescents and adults than children
33
Epidemiology of allergic rhinitis?
- peak prevalence: 14-25 yrs
- 80% develop sxs befpre age 20
- 10-30% of pop affected
- 30-50 mill Americans affected
- loss of 3.5 million work days and 2 million school days
- cost more than 15 bill annually
34
Sxs of allergic rhinitis?
- sneezing
- rhinorrhea
- nasal congestion
- itching of eyes, nose, palate, and ear canals
- postnasal drip, cough
- irritability
- fatigue (not just from meds)
35
How can AR have a significant impact on quality of life and cognitive fxn?
- sleep disordered breathing
- fatigue
- general malaise
- cognitive and psych issues in kids: ADHD, lower exam scores in peak pollen season, poor concentration, impaired athletic performance and low self esteem
36
What diseases are assoc with allergic rhinitis?
- otitis media and eustachian tube dysfxn
- sinusitis
- asthma
- sleep related breathing disorders
37
DDx of allergic rhinitis?
- viral URI
- chronic sinusitis
- adenoidal hypertrophy
- septal deviation
- turbinate hypertrophy
- fbs
- choanal atresia
- nasal polyps
- immunodeficiencies
- CSF leak
- tumors
38
Physical presentation of AR?
- allergic salute: transverse crease across nasal bridge
- allergic shiner: dark swollen, infra-orbital tissue
- Dennie morgan lines: infra-orbital creases due to edema and thickening of skin
- conjunctival chemosis
- cobblestoning in throat and under eyelid
39
AR - manifestations in nose?
- common allergic rxn that causes inflammation in lining of nose
- inflamed nasal lining (appears pale, boggy blue)
- postnasal drip
- clear nasal d/c
40
Dx or AR?
- suggestive hx
- supportive exam
- identify specific IgE
41
Diff b/t sensitization and allergy?
- both skin testing and serum IgE testing detect sensitization - presence of specific IgE to an allergen
- Allergy is a clinical syndrome with sxs combined with evidence of sensitization (Positive skin or serum test)
42
Tx of AR?
- enviro control
- pharm:
antihistamines, decongestants, nasal steroids, anticholinergics, mast cell stabilizers, ocular meds, leukotriene modifiers
- immunotherapy
43
Classification of AR?
- intermittent mild: less than 4 days a week, or less than 4 weeks, mild - normal sleep and daily activities, normal school and work, and no troublesome sxs
- intermittent mod-severe
- persistent mild
- persistent moderate-severe: more than 4 days/week, and more than 4 weeks, will have one or more of the following: abnormal sleep, impairment of daily activities, sports, leisure, problems caused at work and school, troublesome sx
44
Approach to kids under 2 with AR?
- uncommon
| - in all pts avoidance therapy is most effective 1st line therapy
45
Meds approach for kids younger than 2?
- no first gen antihistamines (worried about respiratory depression and death)
- cromolyn nasal spray
- 2nd gen antihistamine: ceterizine, fexofenadine (kids greater than 6 mo)
- intranasal glucocorticoids if severe sxs and no response to above therapies (too much systemic absorption in this young of kids)
46
Med approach for kids older than 2 with mild or episodic sxs?
- cetirizine, loratidine, or fexofenidine: 2-5 hrs prior to exposure
- or intranasal topical antihistamine (azelastine: older than 5, and olopatidine for kids older than 12)
- intranasal glucocorticoid: more effective antihistamines
- or intranasal cromolyn 30 min prior to exposure
47
Med management for kids older than 2 with persistent or severe sxs?
1. intranasal glucocorticoid
2. topical nasal antihistamine
3. oral antihistamine
4. decongestant
- start with 1st med and add on in this order if needed for persistent sxs
48
Intranasal glucorticoids for kids?
- mometasone (nasonex): kids 2 and older
- fluticasone furoate (veramyst): kids 2 and older
- fluticasone propionate (flonase) for kids 4 and older
49
Topical nasal antihistamines in kids?
- Azelastine (Astelin) for kids older than 5
- Olopatidine (patanase) for kids older than 12
- combo azelastine and fluticasone (dymista) older than 12
50
Meds for AR with allergic conjunctivitis?
- intranasal glucocorticoid + topical ophthalmic antihistamine drops
- combo less drying than oral antihistamines
51
Meds for AR with asthma? BBW?
- leukotriene modifier (inhibits mast cell degranulation):
monteleukast (singulair)
approved for use in kids as young as 6 months
- SEs: are depression and suicidal ideations in adults (BBW )
- more common in kids: hyperactive and emotional, anxiousness
