Hypersensitivity disorders Flashcards
what are the primary mechanisms of early and late-phase allergic rhinitis?
- Early phase mechanisms are allergen-induced mast cell secretion of histamine, prostaglandins, and leukotrienes
- late phase mechanisms are eosinophil chemotaxis caused by chemical mediators produced in the early reaction
what is the most common cause of rhinitis during pregnancy?
Pre-existing allergic rhinitis (about one third of women experience worsening of symptoms udring pregnancy)
Why can nasal congestion or rhinorrhea develop in hypothyroidism?
turbinate edema resulting from the release of thyroid-stimulating hormone
Acute onset of unilateral, clear rhinorrhea that is worse when the patient leans forward should prompt evaluation with what test?
check beta-2 transferrin in nasal secretions for suspected CSF rhinorrhea
what is the pathophysiologic mechanism for pale, boggy nasal mucosa in AR?
fluid extravasation leading to mucosal edema and venous constriction
how does allergic fungal rhinosinusitis lead to bone destruction and extension outside the sinuses?
Expansile growth of fungal hyphae and generation of allergic mucin
what lab values can be monitored to assess interval progression of AFRS s/p FESS?
increase in IgE >10% in post-surgical IgE correlate with increase risk of recurrence
what value of total serum IgE is necessary to diagnose AFRS?
total IgE is not one of Bent and Kuhn diagnostic criteria of AFRS.
- need to meet all 5 major criteria
In a patient with recurrent sinusitis and CT findings of pansinusitis and inspissated mucin, what role does SPT to aeroallergens play? (2)
- identification of fungal sensitization
- preparation for post-FESS allergen IT to fungal and nonfungal allergens.
what is ciliary flushing, and in which condition is it found?
- ciliary flushing is an injection of the deep episcleral vessels, causing redness around the cornea
- seen in corneal inflammation, iridocyclitis, and acute glaucoma
what is the treatment of choice for mild to moderate allergic conjunctivitis?
- antihistamine (H1) + mast cell stabilizer
a 10 year old boy is seen for redness of his eyes. He has seasonal allergies and asthma. main complaints include itchy eyes, light sensitivity and feeling like sth is stuck in his eye. His sclera is injected and his R eyelid is lower than his left. what is the diagnosis?
Vernal keratoconjunctivitis
a 45 year old woman presents with ocular pruritus. Also has redness of eyes, difficulty with light, and sometimes pain. She always feels dry and has issues with dry skin. Her eyes feel like leather and she lost her eyelashes. Denies any vision problems requiring glasses or contacts. What is the diagnosis?
Atopic keratoconjunctivitis
sight threatening conditions include all of the following except:
- acute glaucoma
- uveitis
- infective conjunctivitis
- herpes simplex keratitis
infective conjunctivitis
which contact lenses put the wearer at greatest risk for developing giant papillary conjunctivitis?
- hard contact lens
- extended-wear soft contact lens
- daily disposable soft contact lens
- rigid gas permeable contact lens
extended-wear soft contact lens
which subtype of cataracts occur more frequently in patients exposed to glucocorticoids?
posterior subcapsular cataracts
which cytokine is primarily associated with pruritus in atopic dermatitis?
IL-31
what can a person with eczema develop after small pox vaccination?
Eczema vaccinatum (vaccinia virus disseminates to cause an extensive rash and systemic illness).
evidence supports a role of which aeroallergen in AD?
dust mite
which vaccine is contraindicated in severe AD?
small pox vaccine
what do IL-4 and IL-13 do to cathelicidin in the skin?
inhibit cathelicidin expression
which interleukins does dupilumab inhibit?
IL-4 and IL-13
what age group is Dupilumab approved for AD?
6 months and older
what are the causes of delayed peaked reaction (6-7 day) on patch testing? (3)
- metals
- neomycin
- corticosteroids
what is the most frequent infectious cause of asthma exacerbations?
Rhinovirus
what percentage of children will have episodes of wheezing in the first 3 years of life due to viral respiratory tract infections?
50%
sensitization to what aeroallergen in children under 6 years old is associated with development of persistent asthma by age 11 years?
Alternaria
What is part of Asthma Predictive Index (API)? (6)
better NPV than PPV
What is part of Pediatric Asthma Risk Score (PARS)?
better PPV than API
what biomarker can be readily measured and is increased in eosinophilic asthma?
exhaled nitric oxide
what is the cause of skeeter syndrome?
sensitization to mosquito salivary secretions
what immune deficiency is associated with an ice cube negative cold urticaria?
PLAID syndrome (PLC-gamma-2-associated antibody deficiency and immune dysregulation)
false-positive (irritant) results to intradermal testing are more likely above what venom concentration?
> 1 ug/ml. (therefore, not recommended for diagnostic purposes)
a 35 year old female with hives lasting >6 mo complains of intermittent arthralgias and bruises on her arms/legs that are unsightly. What condition should you be concerned about?
- cholinergic urticaria
- urticarial vasculitis
- chronic spontaneous urticaria
- dermatographism
- urticarial vasculitis
what is the febrile illness that occurs in workers after exposure to dust contaminated by toxin-producing fungi in grain, hay and textiles and is 30-50 times more common than farmer’s lung?
Organic dust toxic syndrome (ODTS)
Smoking is an associated risk factor for which agent of occupational asthma?
Platinum (welder, metal/chemical workers)
what is the usual causative agent in hot tub lung?
MAC (mycobacterium avium complex)
what is the most effective treatment for HP?
avoiding offending agent
what two immunizations are critical for COPD patients?
- yearly flu vaccine
- one-time 23-polyvalent pneumococcal vaccine
what medication is associated with red meat allergy (2)
- allergy to Fab segment of cetuximab via an allergy to galactose-alpha-1,3-galactose (alpha-gal)
- tickborne through Lone Star tick in the southeast US.
if severe hypotension occurs after a hymenoptera sting, what key blood test should be done?
tryptase
how many hours does it take for symptoms to peak after the application of a vibratory stimulus to the skin in patients with vibratory urticaria/angioedema?
4-6 hours
20% of patients with hypocomplementemic urticarial vasculitis syndrome (HUVS) have what chronic health conditions? (2)
Asthma and COPD
which medication is considered to be a risk factor for severe reaction to stings?
ACEI
what is the first step in evaluating ABPA in a patient with asthma?
establish IgE sensitization to Aspergillus via skin prick or serum specific IgE
patients sensitized to latex can also have a hypersensitivity reaction to which foods? (7)
ABC
Avocado, Banana, Chestnut, kiwi, white potato, bell pepper and tomato
updated GINA guidelines no longer recommends short-acting beta-2 agonist (SABA)-only treatment for Step 1. What medication should be used in its place for Step 1 treatment?
low dose ICS-LABA
what is the standard maintenance dose for venoms in children?
50 mcg
can you mix honeybee with vespids?
No
How is a definitive diagnosis of EoE made?
endoscopy with esophageal biopsy, >15 eos/hpf
serum total IgE levels usually exceed what level in ABPA?
> 1000 ng/mL (>417 IU/mL)
Within 20 minutes of eating mahi mahi on vacation in Florida, a 39 year old man develops abdominal cramps, vomiting, swelling of tongue and trouble breathing. SPT to all white fish is negative. What is the cause of this illness?
scombroid fish poisoning
what is the classic finding on CT chest in patients with ABPA?
central bronchiectasis and “finger in glove”
which component protein of peanut is a Bet v1 homolog, heat labile and associated with mild OAS-like sx?
Ara h 8
what condition should be evaluated in patients with acute worsening of asthma sx, rise in serum total IgE and serum eosinophils?
ABPA (allergic bronchopulmonary aspergillosis)
a 6 year old boy camping in Texas awakens with diffuse hives, SOB, and wheezing after a painless bug bite. What insect would you be most concerned about?
Triatoma (kissing bug)
what are some common high molecular weight agents that can cause occupational asthma?(9)
- most derived from animals, plants and food
- furry animal proteins, shellfish proteins, flour, wheat, coffee, tobacco dust, psyllium, latex and enzymes (amylase, lipase, pectinase)
Can you mix wasps and vespids?
No
what are the most common food allergies in adults (3)?
- crustacean shellfish
- peanut
- tree nuts
Roofers, insulators, and painters (esp in autobody industry) can develop occupational asthma from being exposed to what?
isocyanates
what are the two most common forms of hypersensitivity pneumonitis?
Farmer’s lung and bird fancier’s lung
what does Toxicodendron cross-react with?
mango peels
- toxicodendron dermatitis (aka poison ivy, oak, and sumac) is the most common form of ACD. it is caused by urushiol, an oleoresin that is found in sap and oozes.
what drugs are commonly implicated in drug-induced ILD? (9)
- Amiodarone, beta blockers, cyclosporine, fluoxetine, heroin, methotrexate, nitrofurantoin, procarbazine, sulfasalazine.
a point mutation in what mast cell gene has been associated with idiopathic anaphylaxis?
an activating point mutation (D816V) in KIT.
exposure to anhydrides is common in what occupation?
manufacturing paint, plastic and epoxy.
what is the allergen in vespids?
Antigen 5 (reverse “V” is similar to “A”)
workers in what field are at risk of occupational asthma due to exposure to plicatic acid? (3)
Woodworkers, carpenters, and mill workers exposed to western red cedar
what is the preferred inhaled corticosteroid for use during pregnancy?
Budesonide
How do you stage a COPD patient with FEV1/FVC ratio of 65% and FEV1 of 45%
GOLD stage 3 or severe COPD
GOLD stage for COPD
what type of emphysema is seen in alpha-1-antitrypsin deficiency?
Panacinar (or panlobular, involving lower lungs)
what is the typical presentation of acute hypersensitivity pneumonitis? (5)
- similar to infectious sx
- abrupt onset (4-6h after exposures) of fever, chills, malaise, nausea, cough, chest tightness, and dyspnea.
- PE: diffuse fine crackles.
- CXR: normal or transient patchy micronodular opacities.
- improvement within 12h to several days after removal of antigen
which cytokines induce isotype switching of B cells to IgE and support eosinophil survival? (3)
Th2 cytokines: IL 4,5,13
Maintenance dose for mixed vespids
300 mcg
what test should be obtained for a young non-smoker with symptoms and signs of COPD?
test for alpha-1-antitrypsin deficiency
what allergen is found in henna tattos?
paraphenylenediamine (PPD)
if a patient has typical sx of COPD but has normal spirometry, what is her stage?
GOLD stage 0 or at risk of COPD
what is typically found in BAL in patients with HP? (2)
marked BAL lymphocytosis (>50%) and CD4/8 ratio <1.0
what is the most common type of interstitial lung disease of unknown cause?
idiopathic pulmonary fibrosis
this protein is produced in eosinophils, appears as a colorless, needle shaped structure and is released in eosinophilic disorders like asthma
Charcot leyden crystals
hairdressers are at risk of developing occupational asthma due to what agents? (3)
persulfate (ammonium) salts
amines
latex
receptor for rhinovirus on T cells that play a role in signal transduction
ICAM-1 (binding of rhinovirus may lead to more severe or prolonged asthma flare)
factors that decrease FeNO (6)
caffeine
smoking
alcohol
CF
pulm HTN
prev use of spirometry
factors that increase FeNO (3)
viral URI
allergic rhinitis
nitrate rich food (like hot dogs)
Diagnostic criteria for asthma using methacholine challenge
measures airway hyperresponsiveness
- PC20 <4 mg/mL is diagnostic
- 4-16mg/mL suggestive if appropriate sxs are present
.
.
name three validated tools of asthma control
- asthma control questionnaire (ACQ)
- asthma control test (ACT)
- asthma therapy assessment questionnaire (ATAQ)
SMART management for asthma flare
- use of low-med dose of budesonide/formoterol for relief and maintenance
- reduce asthma flare and less ICS exposure
a short course of daily ICS for 0-4yo with recurrent viral-induced wheezing is recommended by?
EPR-3
what is a well-known complication of acute asthma flare?
PTX
onset of sx for exercise induced asthma (2)
10 min after aerobic activity, resolve by 15-30 min after
- FEV1 dec by >15% after exercise
lung volume changes in pregnancy
- inc minute ventilation (compensated resp. alkalosis) due to inc progesterone
- inc TV, dec RV and FRC (functional residual capacity)
EPR-3 classification of moderate persistent asthma severity for 0-4 yo
- daily sx
- 3-4 night time sx/month
- daily use of SABA
- some limitation in normal activity
- > 2 flares/6mo OR >4 wheezing/1yr AND risk factors
- recommended step is Step 3 and consider oral steroids
EPR-3 classification of not well controlled asthma for 0-4 yo
- sx >2d/week
- night-time sx >1/mo
- some interference with normal activity
- SABA use > 2d/weel
- exacerbations 2-3x/yr
- recommended tx = one step up
EPR-3 classification of moderate persistent asthma severity for 5-11 yo
daily sx
night time >1x/week
daily SABA use
some limitation
FEV1 60-80%; FEV1/FVC 75-80%
>2 excerbations/yr
Step 3 tx, consider oral steroids
EPR-3 classification of not well controlled asthma for 5-11 yo (7)
sx >2x/week
night time >1x/month
some limitation
SABA use >2d/week
FEV1 60-80%
2-3 excerbations/yr
tx one step up
EPR-3 classification of moderate persistent asthma severity for >12 yo
daily sx
night time >1x/week
daily SABA
some limitation
FEV1 60-80%; FEV1/FVC dec by 5%
>2 exacerbations /yr
step 3, consider oral steroids
EPR-3 classification of not well controlled asthma for >12 yo
sx >2d/week
night time 1-2x/week
some limitatino
SABA >2d/week
FEV1 60-80%
ATAQ 1-2/ ACQ>1.5/ ACT 16-19
>2 exacerbations/yr
tx one step up
EPR-3 stepwise approach tx for 0-4yo. Step 1 and 3 (1,3)
step 1 = SABA PRN +daily ICS at the start of sx
step 3 = daily low dose ICS/LABA
low dose ICS+montelukast
med-dose ICS
EPR-3 stepwise approach tx for 5-11 yo. Step 1 and 3
step 1 = SABA prn
step 3 = low dose ICS/formoterol
med-dose ICS
low dose ICS/LABA
low dose ICS + LTRA
low dose ICS/theophylline
EPR-3 stepwise approach tx for >12yo. Step 1 and 3
step 1 = SABA prn
step 3= low dose ICS/formoterol
med dose ICS
low dose ICS/LABA
lose dose ICS+LAMA
low dose ICS +LTRA
low dose ICS + theophylline or zileuton
GINA 2020 stepwise approach tx for 0-4yo. Step 2 and 3
step 2 = daily low dose ICS // daily LTRA // intermittent short courses of ICS at onset of sx
Step 3 = double low dose ICS
low dose ICS +LTRA
SABA prn
GINA 2020 stepwise approach tx for 6-11yo. Step 1 and 3
step 1 =low dose ICS + SABA prn // daily low dose ICS
step 3 = low dose ICS/LABA // med dose ICS
low dose ICS + LTRA
GINA 2020 stepwise approach tx for >12yo. Step 1 and 3
step 1 = low dose bud/formeterol prn // low dose ICS+SABA
step 3 = low dose ICS/LABA
med dose ICS
low dose ICS + LTRA
(preferred reliever is bud/form)
MOA of benralizumab (2)
- binds to IL5Ralpha
- induce apoptosis of eos via interaction with NK cells by Ab dep cell mediated cytotoxicity
characteristics of class 1 food allergens (6)
glycoproteins
glycosylation residue
heat resistant
acid stable
stable to proteases
water soluble
characteristics of class 2 food allergens (3)
plant derived
labile
due to allergic sensitization to inhalant allergens
linear epitope is associated with
more prolonged allergy and more stable/persistent allergen
proteins and food allergens of milk
casein - Bos d 8 - major allergen, more persistent
whey (lactoglobulins) - Bos d 4-6 - heat labile
egg white proteins and allergens
ovomucoid - Gal d 1 - more persistent. best predictor of reaction to heated egg
ovalbumin - Gal d 2 - heat labile. associated with outgrowing egg allergy
ovotransferrin - Gal d 3 - heat labile
peanut protein and allergens (8)
vicilin (seed storage protein) - Ara h 1 - major. heat stable
conglutin (seed storage) - Ara h 2, 6, 7 - major, heat stable
glycinin (seed storage) - Ara h 3 - major. heat stable
profilin/ Bet v 2 homolog - Ara h 5 - heat labile
Bet v 1 homolog - Ara h 8 - heat labile. OAS
lipid transfer protein - Ara h 9 - stable protein
oleosin - Ara h 10, 11
defensins - Ara h 12, 13 - associated with severe anaphylaxis
soy bean protein and allergens
Bet v 1 homolog - Gly m 3,4 - mild sx and OAS
storage proteins - Gly m 5,6 - severe rxn