Asthma Flashcards
Prevalence
Asthma can present at any age with a peak age of……….
3 yrs
Male/Female ratio
In childhood: M/F=2/1
With a trend toward greater prevalence in women in adulthood.
Adults with asthma, including those with onset during adulthood
rarely become permanently asymptomatic
Use of………… is responsible for the decrease in mortality in recent years.
ICSs
Major risk factors for asthma deaths are:
-Poorly controlled disease with frequent use of bronchodilator inhalers
-Lack of corticosteroid therapy
-Previous admissions to the hospital with near-fatal asthma.
Phathology of asthma
Mucus production
Epithelial shedding
Neuronal proliferation
Airway edema
Cellular proliferation
SM construction
Inflammatory cells in asthma
Most commonly eosinophilic inflamation
In some patients with severe asthma , neutrophilic inflammation is predominant
Airway smooth muscle cells can produce
chemokines and cytokines.
Is more commonly seen in severe asthma Has not responded to the common anti-inflammatory therapies such as corticosteroids,
Non -type 2 asthma
Tobacco
Maternal smoking & second hand smoke exposure Increased childhood asthma (2 fold)
Active smoking in adolesc. & Adults Inc.4 fold
Air pollution
CO & NO2 and marginal effect of SO2
associated with development of asthma
in children(Rhinovirus & RSV)
prior Mycoplasma Pneum.
Occupational Exposure
2 types of exposures are:
1- Immunologic stimulus:
Latency period between exposure & symptoms
A-High molecular weight : Proteins-Flour
B-Low molecular weight : Formaldehyde - Diisocyanate
2-Irritative stimulus
Known as RADS(Reactive Airways dysfunction syndrome)
At obesity
Adipokines & IL6 thought to play a pathobiologic role.
Medications
(H2 blockers & Proton pump Inhibitors & Acetaminophen) in pregnancy , risk on the child
ABPA
In air , soil , organic matter
2% of patients with asthma may have IgE mediated sensitization to colonozation of the airway by fungi.(Aspergillus Fumigatus)=ABPA
-Type 2 airway inflammatory response
-IgE>1000IU/ml
-Eosinophil>500/microlit
-Positive skin test to A.F.
-Mucous plug
-Central bronchiectasis
ABG
HCO3-
Pco2
Po2
Sat o2
Endogenous developmental risk factors
More prevalent among boys than girls.
-Atopy is more prevalent among boys
-Reduced airway size among boys
•Difference receding by age 20.
•More prevalent among women by age 40.
•Develop asthma around menopause.
Reactive airways dysfunction syndrome (RADS)
High concentration irritant exposure cause Bronchospasm (whitin hours) .
Oxidizing & Reducing aerosolized agents cause Epithelial injury & Neutrophilia
………….can cause asthma for 4-6 weeks
But maybe 🤔 permanent
Upper respiratory tract virus infections.
•Neutrophilic or eosinophilic inflammation.
Exercise is a common trigger , particularly in children.
The mechanism is Hyperventilation which causes increased osmolality in airway lining fluids & triggers mast cell mediator release resulting in bronchoconstriction
EIA is worse in cold, dry climates.
Autonomic innervation of lungs
Sym………beta………muscle relaxation ………bronchodilation
Parasym………muscarin………muscle contraction ………bronchoconstriction
Pregnancy can worsen asthma in……… of patients.
1/3
Most patients with Gastro-esophageal Reflux …………therapy fails to reduce asthma symptoms in most patients.
Anti-reflux
