week 6- allergy Flashcards
allergy definition
the clinical manifestation of an adverse immune response after repeated contact with a typically harmless substance (e.g., pollens, mold spores, animal dander, dust mites, foods, stinging insects), regardless of mechanism
atopy definition
the predisposition to an immune response against antigens and allergens, leading to CD4+ Th2 differentiation and overproduction of IgE (Type 1 hypersensitivity reaction)
what T cell, type of hypersensitivity rxn and Ig_ are in atopy
CD4+ Th2
IgE
type 1 hypersensitivity
allergic rhinitis defintion
an inflammation of the nasal mucous membranes caused by an IgE-mediated response to exposure to one or more allergens
Ig_ in allergic rhinitis
IgE
common manifestations of atopy
allergic rhinitis, asthma, eczema
allergic rhinitis is classified as
as a component of systemic allergic response (e.g., asthma, atopic dermatitis) – with an underlying systemic pathology
(not just nasal airway alone)
allergic rhinitis prevalence
20-30% adults, 40% kids
gency for Healthcare Research and Quality (AHRQ) said allergic rhinitis is ___ most prevalent chronic illness
6th
one of the most chronic pediatric disorders
allergic rhinitis
greatest onset of allergic rhinitis in
adolescence
risk factors for allergic rhinitis
genes
location, season
family history of atopy,
male sex,
a presence of allergen-specific IgE,
a serum IgE greater than 100IU/mL before age 6,
higher socioeconomic status
1st year of life: early introduction of foods and formula, cigarette exposure
protective factors for allergic rhinitis
breastfeeding, early pet exposure, “farm effect”
impact of allergic rhinitis
school + work, sleep, fatigue, productivity, economic costs (medications…)
diminished quality of life
diagnosis of allergic rhinitis via
Patient history
Symptoms
Physical examination findings
Allergy testing
pt history for allergic rhinitis
age of onset
symptoms (onset, duration, exposures, magnitude of reaction, patterns, chronicity); exacerbating/alleviating factors; seasonal variation; environmental influences; allergies; medical history; and past and current treatments
constitutional sx (headahe, malaise, fatigue)
asthma hx
seasonal? persistent (could be indoor allergen)?
acute onset if think allergic rhinitis is probably
(one week or less) usually suggests a viral etiology, acute exacerbation of allergic rhinitis, or possibly a foreign body (more commonly unilateral and in children)
chronic allergic rhinitis often has
postnasal drip, chronic nasal congestion, and obstruction
anaphylactic rxn from food or insect sting indicated
atopy
antihistamine and intranasal corticosteroids for
allergy
medications that can lead to allergic rhinitis sx
Beta-blockers, acetylsalicylic acid, NSAIDs, ACE inhibitors, and hormone therapy
common allergens
pollens, furred animals, textile flooring/upholstery, tobacco smoke, humidity levels at home, other noxious substance exposure
seasonal allergic rhinitis caused by
pollens and spores
Flowering shrub and tree pollens in the spring; flowering plants and grasses in the summer; and ragweed and molds in the fall
perennial rhinitis
Dust, household mites, air pollution, and pet dander may produce year-round “perennial rhinitis”
allergy and atopy tend to be
hereditary
genes influence sensitization and production of IgE antibodies
major causes of allergic rhinitis and combordities (atopic dermatitis, otitis media with effusion and asthma) in kids and infants
vs older kids and adolescents
allergens (e.g., milk, eggs, soy, wheat), dust mites, and inhalant allergens (e.g., pet dander)
older: pollen allergies
clinical manifestations of allergic rhinitis
sneezing paroxysms
transverse nasal crease
infraorbital cyanosis (allergic shiners)
nasal, ocular and palatal itching
clear rhinorrhea
serous otitis media
nasal congestion
pain, bluish nasal mucosa
lab findings: nasal eosinophilia, evidence of allergen specific IgE by skin or RAST
symtptoms in allergic rhinitis
Nasal congestion, clear rhinorrhea, sneezing, postnasal drip, and nasal pruritis
Allergic conjunctivitis: eye irritation and excessive tearing (more commonly associated with animal and outdoor allergens)
associated sx:
Chronic sinusitis, nasal polyposis
Non-productive cough, bronchospasm, eczematous dermatitis
Snoring, sleep apnea, sleep disturbance
Headache, difficulty concentrating, low mood, fatigue
associated sx of allergic rhinitis in children
Malaise or fatigue may be presenting complaints in children
Sinusitis, Eustachian tube dysfunction and otitis media with effusion
Asthma
Snoring
Possible dental overbite and high-arched palate due to chronic mouth breathing
physical exam for allergic rhinitis
Visualization of patient’s appearance (allergic shiners, eye conjunctivitis, mouth breathing, sniffing)
Nose (nasal salute; transverse nasal crease)
Ears (Eustachian tube dysfunction)
Sinuses (tender)
Posterior oropharynx (post nasal drip, enlarged tonsils inversely associated with allergic rhinitis)
Additional: Lymph Nodes (rule out viral or bacterial if lymphadenopathy), Chest (wheezing= asthma) and Skin (dermatitis)
findings on endoscopic nasal exam for allergic rhinitis
structural abnormalities (e.g., septal deviation, nasal ulcerations, and nasal polyps)
“Cobblestoning” of nasal mucosa, mucosal swelling, and discharge
Boggy, pale, or “bluish” (violaceous) nasal turbinates due to venous engorgement
Consider assessment before and after decongesting with a topical decongestant for comparison
nasal polyposis
chronic inflammation of paranasal sinus mucosa; bilateral, benign
child physical exam findings for allergic rhinitis
allergic shiners
facial grimacing
mouth breathing
nasal salute
concomitant otitis media with effusion
allergy testing
choose tests that change treatment plans
empiric treatment ok if classic sx
severe sx or unclear do diagnostic tests
if pt a candidate for allergen avoidance treatment of immunotherapy
3 types of allergy testing
skin testing
–> skin prick
–> intradermal
serum testing (IgE)
primary method for identifying specific allergic triggers of rhinitis
skin testing
what medciations can interfere with skin testing
H2-receptor antagonists, tricyclic antidepressants, and anti-IgE monoclonal antibody omalizumab
contraindications for skin testing
patients with uncontrolled or severe asthma, unstable cardiovascular disease, pregnancy, concurrent beta-blocker therapy
what rxn does skin testing do and whats it caused by
immediate allergic response caused by the release of mast cell or basophil IgE-specific mediators, which create the classic wheal-and-flare reaction
skin testing gives what on skin
wheal and flare rxn
skin prick step
extract of allergen on skin
prick epidermis
15-20 min –> wheal and flare (+)
whats more sensitive and provides more consistent results; skin prick or intradermal?
intradermal
intradermal testing involves
injection of a small amount (max 0.05mL) of the suspected allergen under the surface of the skin, in order to raise a bleb 4-6mm in diameter
wait 15-20 min
get small hive with swelling and redness
wheal >3mm beyond initial bleb is positive
skin rxn from intradermal testing
small hive with swelling and redness
wheal >3mm
+ and - result for intradermal testing
+ increase wheal >3mm beyond initial bleb
- : bleb that hasn’t increased but persisted and itchy and flare
serum testing of IgE fro
atopic allergy
serum testing
- Though the original in-vitro assay the radioallergosorbent (RAST) test is no longer performed, the name is still used to generally describe IgE-specific blood testing
efficacy of serum testing
equivalent to skin testing
px must stop taking what before serum testing
antihistamines
allergy testing for kids
Conclusion: percutaneous skin testing is appropriate for children 3 years and older, and RAST testing is appropriate at any age
Recommendation: base testing decisions on clinical history and perform tests only when needed to change therapy or clarify a diagnosis
which test for kids >3yoa and kids at any age
percutaneous skin testing is appropriate for children 3 years and older, and RAST testing is appropriate at any age
nasal cytology used if
diagnosis of allergic rhinitis is unclear
where is nasal cytology sample from
middle part of inferior turbinate of both nostrils
nasal cytology findings
presence of inflammatory cells (eosinophils, mast cells, neutrophils, and plasma cells) infiltrating the nasal mucosa and releasing chemical mediators, is thought to be responsible for the main symptoms of allergic rhinitis (e.g., itching, nasal congestion, runny nose, sneezing)
ddx for congestion and rhinorrhea
common cold
sinusitis
viral
allergic
bacterial
fungal
seasonal allergic rhinitis
vasomotor rhinitis
rhinitis secondary to a-agonist withdrawal
drug-induced rhinitis (i.e. cocaine)
nasal foreign body
types of allergic rhinitis
seasonal
perennial
types of infectious rhinitis
viral
bacterial rhinosinusitis
miscellaneous types of rhinitis
granulomatous rhinitis
atrophic rhinitis
gustatory rhinitis
types of nonallergic, noninfectious rhinitis
eosinophilic syndromes
-NARES
-nasal polyposis
noneosinophilic syndromes
-vasomotor rhintiis
-rhinitis medicamentosa
-occupational rhinitis
-rhinitis of pregnancy
-hypothryoidism
-medication (i.e. birth control)
nonallergic rhinitis examples
- Viral upper respiratory infections
- Vasomotor rhinitis
- Rhinitis medicamentosa
- Hormonal and drug-induced rhinitis
- Nonallergic rhinitis with eosinophilia syndrome
nonallergic rhinitis diagnosis is made after eliminating
allergic or IgE mediated causesm
most common cause of nonallergic rhinitis
acute viral infection
less common causes of nonallergic rhinitis
vasomotor rhinitis, drug-induced rhinitis, rhinitis medicamentosa, hormonal rhinitis, non- allergic rhinitis with eosinophilia syndrome
what is the mechanism behind nonallergic rhinitis
nociceptor and autonomic nerve dysregulation
who is nonallergic rhinitis more common in
women, >35yoa, no family hx of allergies
acute viral rhinitis (rhinosinusitis) main causes
rhinoviruses, respiratory syncytial virus, parainfluenza, influenza, adenoviruses
sx of acute viral rhinitis (rhinosinusitis)
sx of viral illness (e.g., headache, malaise, body aches, cough)
Nasal drainage is most often clear or white, and can be accompanied by nasal congestion and sneezing
treatment of acute viral rhinitis (rhinosinusitis)
self limiting; symptomatic treatment
bacterial infections that cause superinfection of rhinosinusitis
Streptococcus pneumoniae, group A beta- hemolytic streptococci, Haemophilus influenzae
- Symptoms generally worsen (e.g., facial pain, nasal obstruction, fever)
vasomotor rhinitis theory
increased blood supply to the nasal mucosa, although this has not been proven
cause of vasomotor rhinitis
abnormal autonomic regulation of nasal function
compounding factors for vasomotor rhinitis
previous nasal trauma and extraesophageal manifestations of GERD
sx of vasomotor rhinitis
congestion, clear nasal drainage, and (less commonly) pruritus and sneezing
vasomotor rhinitis is not from
specific allergen, infection or casue
vasomotor rhinitis include px with
perennial symptoms that are associated with temperature changes, humidity, odours, alcohol ingestion, and eating (“gustatory rhinitis”)
diagnosis of vasomotor rhinitis
A diagnosis of exclusion: patients should have normal serum IgE levels, negative skin testing or RAST, and no inflammation on nasal cytology
drug induced rhinitis from
antihypertensives, NSAIDs, phosphodiesterase-5 inhibitors, cocaine
example of drug induced rhinitis
Rhinitis medicamentosa
Rhinitis medicamentosa sx
nasal obstruction that worsens over years
use of topical vasoconstrictive nasal sprays and need to increase dose (tachyphylaxis)
rebound rhinitis from sprays
hormonal rhinitis is associated with
pregnancy
how does pregnancy cause hormonal rhinitis
systemic concentration of estrogen rises throughout pregnancy, leading to an increase in hyaluronic acid in the nasal tissue, with subsequent increase in nasal edema and congestion
Additionally, there is an increase in mucous glands and decrease in nasal cilia during pregnancy – this heightens nasal congestion and decreases mucous clearance
when is hormonal rhinitis worst in pregnancy
2nd and 3rd trimester
rhinitis with nasal eosinophilia syndrome
[Nonallergic rhinitis with eosinophilia (NARES)] definition
Inflammatory type of rhinitis with increased eosinophils in secretions and increased mast cells with degranulation (on nasal biopsy)
sx of Nonallergic rhinitis with eosinophilia (NARES)
nasal obstruction, congestion, sinusiits, polyposis
do you test for eosinophils in rhinitis with nasal eosinophilia syndrome
Testing secretions for eosinophils is not typically performed because their presence/absence does not help distinguish allergic from nonallergic etiologies or change treatment management
nonallergic rhinitis vs allergic rhinitis
some have a combination rhinitis of both
how to see if patient has combination rhinitis (nonallergic and allergic)
patient rhinitis screen tool
3 subgroups of allergic rhinitis
Seasonal
Perennial
Occupational
seasonal rhinitis from
pollination of plants
Trees = spring;
grasses = late spring and summer;
weeds (and molds) = fall
sx of seasonal rhinitis
sneezing; watery rhinorrhea; itching of the nose, eyes, ears, and throat; red and watering eyes; and nasal congestion
worse in morning
aggravated by dry + wind
perennial rhinitis
constant sx
more prevalent in adults
sx of perennial rhinitis
nasal congestion and blockage; and
postnasal drip
- Rhinorrhea and sneezing are less common
- Eye symptoms are less common, except with animal allergies
- Seasonal pollen may exacerbate any of these symptoms
common allergens for perennial rhinitis
indoor inhalants – predominantly
dust mites, animal dander, mold spores, and cockroaches
occupational
food allergens (often sx; GI issues, urticaria, angioedema, anaphylaxis)
infections (ie. respiratory tract –> rhinosiunsitis, otitis media with effusion)
irritants: tobacco smoke, chemical fumes, air pollutants
systemic sx of seasonal and perennial allergic rhinitis
malaise, weakness, fatigue
allergic conjunctivitis, Asthma, eczema
seasonal vs perennial classification of allergic rhinitis
Some allergic triggers (e.g., pollen) may be seasonal in cooler climates but perennial in warmer climates
Patients with multiple “seasonal” allergies may have symptoms throughout most of the year
Classification by symptom duration (intermittent or persistent) and severity (mild, moderate, or severe) is preferred
2 exposures in occupational rhinitis and examples
Allergen-related = allergic rhinitis category (e.g., laboratory animals, latex, grains, coffee beans, wood dust)
Irritant-related = more accurately nonallergic rhinitis (e.g., tobacco smoke, cold air, formaldehyde, hair spray)
sx of occupational rhinitis
nasal dryness, congestion, rhinorrhea, and sneezing
in occupational rhinitis with chronic exposure to cigarette smoke and wood particles what has been seen in the nose
decreased ciliary movements
how to help occupational rhinitis
Environmental control by limiting exposure through removal of the causal agent, avoidance, improving ventilation, and the use of protective particulate respirator masks
effect on climate change on allergic rhinitis via
increased temp and carbon dioxide –> increased pollen production with stronger allergenicity in ragweed plants
extended summers = longer periods of pollen production in flowering seeds
classify allergic rhinitis based on 2 things
duration and severity
duration of allergic rhinitis
intermittent vs persistent
Intermittent: < 4 days/week or < 4 weeks’ duration
Persistent: ≥ 4 days/week or ≥ 4 weeks’ duration
severity of allergic rhinitis
mild vs moderate-to-severe
Mild: symptoms are present but not troublesome; no impairment in daily activities, school or work; and no sleep disturbance. Minimal changes in quality of life.
Moderate-to-severe: one or more is present of troublesome symptoms; impairment in daily activities, school or work; or sleep disturbance. Significant changes in quality of life.
FLOW CHATY ON SLIDE 111 for diagnosis
:)
atopy definition
is the genetic predisposition to developing allergic conditions, such as atopic dermatitis, asthma, allergic rhinitis, food allergies
atopy has the presence of
allergen-specific IgE
what cells and rxn type play a role in atopy
mast cells
hypersensitivity rxn (urticaria and anaphylaxis)
atopic triad
atopic dermatitis + allergic rhinitis + asthma
sx of atopic triad
Immediate and late cellular phase of allergic inflammation in the skin, nose, or lung with allergen exposure in sensitive individuals
atopic march
progression from atopic dermatitis to allergic rhinitis to asthma during childhood
atopic march 2 steps
(skin to food to nose to mouth)
Step 1: Birth to 1 year: Skin irritation (hives, eczema)
Step 2: 1-3 years: Food allergies
* Top 8 are peanut, tree, nut, cow’s milk, egg, wheat, soy, fish, and shellfish
Step 3: 4-6 years: Seasonal and environmental allergies, including allergic rhinitis
Step 4: 5-7 years: Asthma
___% of Canadians with asthma also suffer from allergic rhinitis or sinusitis
80%
allergic rhinitis and sinusitis are associated with
more severe or frequent asthma symptoms
what 2 conditions frequently overlap
asthma + allergic rhinitis
several same allergen triggers
what makes asthma worse
seasonal allergies
(treat seasonal allergies to reduce asthma sx or development)
asthma pathophysiology mechanism
intrinsic hyperreactivity of the airways independent of the associated inflammation
management of allergic rhinitis
if dont respond to standard therapy then do specialist (but usually primary care dr.)
or refer if have findings like: many nasal polyps (cystic fibrosis), bloody or unilateral discharge (malignancy), CSF leak to rhinorrhea
when to refer to specialist in allergic rhinitis
- Multiple nasal polyps in a pediatric patient is suggestive of cystic fibrosis
- Bloody or unilateral nasal discharge should be referred to an ENT to rule out malignancy
- Any concerns of cerebrospinal fluid leak causing rhinorrhea
