Asthma II Part 1: Triggers, Comorbidities Flashcards
Asthma Phenotypes
name 3 common ones
no strong relationships has been found between specific
pathological features and particular clinical patterns or treatment responses
Allergic asthma: Most easily recognized, starts in childhood. Associated with past or family history of allergic disease (atopic dermatitis, allergic rhinitis) Inhaled corticosteroids (ICS) are helpful.
Non-allergic asthma: Not associated with allergy. Sputum may contain only a
few inflammatory cells. Less short term response to ICS
Adult onset asthma: Incidence higher in women. Asthma for the first time in adult life. Tends to be non-allergic and requires higher doses of ICS. Rule out
Work Related Asthma.
what are asthma triggers and what are the types?
things which worsen asthma symptoms
• They may or may not be easily identifiable
• Each patient with asthma will have slightly different asthma triggers
Triggers may be inflammatory or non-inflammatory
• Non-inflammatory triggers to lead to bronchoconstriction alone (no inflammatory response)
Triggers may be allergens or irritants
• Allergens cause an allergic cascade of events whereas irritants do not
Inflamm triggers
Aeroallergens (substances in the air)
Bind to IgE in sensitized individuals and ultimately activates histamine release along with other mediators, like leukotrienes
- Once sensitized, re-exposure to these aeroallergens can trigger an exacerbation and symptoms of asthma (occurs via T-Helper 2 cell recruitment, mast cell activation through IgE, and eosinophil influx)
- e.g., animal secretions, house dust mites, molds, cockroaches, pollens
Inflamm triggers
Viral (RSV, rhinovirus, influenza) or bacterial infections
- Asthma exacerbations that occur in conjunction with an upper or lower respiratory tract infection may be more severe than exacerbations that occur without concomitant infection.
- Epidemiologic studies suggest that viruses provoke asthma attacks by additive interactions with allergens or irritants such as air pollutants
Inflamm triggers
Air Pollutants
• Outbreaks of asthma exacerbations have been shown to occur in relationship to increased levels of air pollution
Inflamm triggers
Occupational Sensitizers
- Over 300 occupational sensitizers
- Long term exposure, causes a development of an immunological mediated response to the trigger (IgE- and cell mediated allergic reactions)
- Occupational asthma is common in farming and agriculture work, painting, cleaning, and plastic manufacturing
Inflamm triggers
Tobacco and Cannabis smoke
• First- (smoke inhaled by smoker), second- (exhaled smoke inhaled by others, or third-hand exposure (smoke left on surfaces of objects)
name 5 inflamm triggers
Aeroallergens Viral (RSV, rhinovirus, influenza) or bacterial infections Air Pollutants Occupational Sensitizers Tobacco and Cannabis smoke
non-inflamm triggers
Medications
- Agents most commonly associated include ASA, NSAIDs such as ibuprofen or naproxen, and non-cardioselective β-blocker
- Approximately 5% to 10% of adult patients with asthma will have an acute worsening of asthma symptoms after ingesting an NSAID
- Symptoms may include: rhinorrhea, lacrimation, bronchospasm
non-inflamm triggers
emotions
- Hyperventilation can cause airway narrowing
- Stress, crying and laughing can trigger symptoms because breathing patterns change
- Psychosocial
- Inappropriate asthma self-care, a disregard for asthma symptoms
non-inflamm triggers
Hormonal changes
- Women may experience greater symptoms during menstruation
* In pregnancy, 1/3 of asthma worsens, 1/3 improves, and1/3 stays the same
non-inflamm triggers
other (4)
- Food additives (MSG)
- Cold air / weather conditions
- Physical activity (very common)
- Strong fumes (perfumes, paints, etc.)
name 4 non- inflamm triggers
meds
emotions
hormonal changes
other (weather, food, phys activity, fumes)
Comorbidities
Rhinitis and sinusitis
• Rhinitis frequently precedes asthma and is both a risk factor for the development of asthma and is associated with increased asthma symptom severity
patients with allergic rhinitis is estimated to be 17% to 38%, and prevalence of rhinitis in patients with allergic asthma to be between 60% and 80%
Comorbidities
Atopic dermatitids
define atopy
management of atopic dermatitis may reduce severity of later asthma
• Atopy: propensity to produce specific IgE antibodies to common aeroallergens
strong association between atopic dermatitis and asthma in childhood and a similar association seen later in life.
• Association between atopic dermatitis and the development of allergic rhinitis
FYI - Approximately 40% to 60% of children with atopic dermatitis will
develop allergic rhinitis and/or asthma over time
Comorbidities
GERD
which drugs can make GERD worse>?
Relationship is not fully understood (it is unlikely in children)
- asthma - higher prev of GERD
- GERD could worsen asthma either by direct effects on airway responsiveness or via aspiration induced inflammation
- beta-agonists and methylxanthines used in the
treatment of asthma can impair function of the lower esophageal sphincter
GERD-induced cough does respond to the use of full dose PPIs in twice daily dosing, but it often takes up to three months for a response
PPI don’t help manage asthma
Comorbidities
food allergies
see table for food additives commonly associated with allergies (extra)
no conclusive evidence demonstrating a change in
any dietary factor can prevent or exacerbate asthma
- Ability of these agents to exacerbate asthma is probably minimal for most patients with asthma, and for this reason food avoidance should not be recommended until allergy confirmed
Comorbidities
obesity
what improves asthma?
- linked to asthma persistence and severity in both
children and adults - effects of obesity on asthma independent of diet and physical activity, although these three factors are clearly interrelated
- Weight reduction in obese patients with asthma has been shown to improve lung function, symptoms, morbidity, and health status
- pt may have suboptimal response to therapy
5 unique circumstances for asthma
- Exercise-induced bronchoconstriction (EIB)
- Work-related asthma (WRA)
- Perimenstrual asthma (PMA)
- Asthma in pregnancy
- Aspirin®-exacerbated respiratory disease (AERD)
Exercise-Induced Bronchospasm (EIB)
what is it not called?
occurs in who?
what 2 factors most important?
Acute airway narrowing that occurs as the result of exercise
• Also called exercise-induced asthma (EIA), although this term is not used as often because there may not be underlying chronic asthma, nor does exercise “cause” asthma.
occurs in:
- patients with mild, stable asthma where exercise is the only known trigger
- thletes who don’t appear to have underlying asthma
- olympic atheles common, more in endurance sports
- humidity of air and level of exercise (vigour and duration) most important
Exercise-Induced Bronchospasm (EIB)
MOA?
MOA unknown
- stimulus is respiratory heat loss, water loss or both, causes changes in air wall osmolality which causes mast cell degranulation, prostaglandin, leukotrienes and histamine release, and airway
hyperresponsiveness
Exercise-Induced Bronchospasm (EIB)
Clinical presentation
FEV decrease of?
Chest tightness, cough, wheezing, and dyspnea
• It is defined as a transient narrowing of the airways that follows vigorous
exercise (it rarely occurs during exercise)
• There may be no increase in inflammatory cell recruitment if ppl don’t have asthma
FEV1 decrease of 15% from baseline
Exercise-Induced Bronchospasm (EIB)
Diagnosis
how is it measured?
time it usually occurs?
- wheeze, chest pain (primarily in children) or chest tightness, shortness of breath, dyspnea, excessive
mucus production, or feeling out of shape when they are actually in good physical condition - minutes after vigorous activity, reaches its peak
five to ten minutes after stopping the activity, and resolves in another
20 to 30 minutes - diagnose by change in FEV1 following exercise (spir)
Work-Related Asthma (WRA)
what are the 2 types
- Occupational asthma = asthma that is caused by work
- 2 types - Work-exacerbated asthma = asthma that pre-exists and is triggered by the workplace either by irritants or aeroallergens.
