Asthma Flashcards
What is the peak age of onset for bronchial asthma?
3 years
What are two key defining features of bronchial asthma?
Variable respiratory symptoms and variable expiratory airflow limitation, usually reversible.
What spirometric findings indicate obstructive ventilatory impairment in asthma?
Low FEV1 and FEV1/FVC ratio.
What increase in FEV1 after bronchodilator inhalation denotes reversibility?
> 200 mL and >12% increase.
List three common endogenous risk factors for asthma.
Genetic predisposition, airway hyperresponsiveness, obesity.
Name three environmental triggers for asthma exacerbation.
Indoor allergens, passive smoking, respiratory infections.
What is atopy, and how is it related to asthma?
Atopy is an exaggerated IgE-mediated immune response to allergens and a major risk factor for asthma.
Which interleukins are associated with asthma and atopy on Chromosome 5q?
IL-4, IL-5, IL-9, and IL-13.
What is the ‘hygiene hypothesis’ in the context of asthma?
It suggests that exposure to endotoxins and infections results in a protective TH1 immune response, reducing asthma risk.
How does obesity contribute to asthma?
Pro-inflammatory adipokines from fat stores and reduced anti-inflammatory adipokines worsen asthma control.
Name the clinical features characteristic of asthma.
Wheezing, dyspnea, coughing, worse at night, and increased mucus production.
What is ‘cough-variant asthma’?
A form of asthma where the primary symptom is a non-productive cough.
What is the significance of a positive methacholine or histamine challenge test in asthma diagnosis?
It confirms airway hyperresponsiveness.
What are the major types of asthma phenotypes?
Allergic asthma, non-allergic asthma, late-onset asthma, asthma with fixed airflow limitation, and asthma with obesity.
Which drugs are classified as short-acting beta-agonists (SABAs)?
Albuterol and terbutaline.
What is the primary function of long-acting beta-agonists (LABAs)?
They provide bronchodilation with a duration of 12-24 hours and are used for maintenance therapy.
What are two key side effects of inhaled corticosteroids (ICS)?
Oral thrush and dysphonia.
How does omalizumab work in asthma therapy?
It is an anti-IgE biologic agent that reduces IgE levels and allergic responses.
What is brittle asthma, and what are its two types?
A severe form of asthma with chaotic lung function variability; Type 1 involves persistent variability, and Type 2 involves sudden unpredictable lung function falls.
What constitutes uncontrolled asthma based on the asthma control questionnaire?
Daytime symptoms more than twice/week, night waking, reliever needed more than twice/week, or activity limitation due to asthma.
What is the first-line treatment for acute severe asthma?
High doses of short-acting beta-agonists (SABAs) via nebulizer or pMDI with spacer.
What is the role of magnesium sulfate in asthma management?
It is given intravenously or nebulized in severe asthma not relieved by initial therapy to reduce bronchoconstriction.
What differentiates asthma-COPD overlap (ACO) from asthma or COPD alone?
ACO shows features of both diseases, such as airway hyperreactivity and partially reversible airflow limitation.
What is the mechanism of action of theophylline in asthma?
It inhibits phosphodiesterases, increasing cyclic AMP, and has anti-inflammatory effects at lower doses.
What is the most common genetic predisposition implicated in asthma?
Polymorphisms of genes on Chromosome 5q, including those affecting TH2 cells and interleukins.
What structural changes occur in the airway during asthma?
Thickened basement membrane, airway smooth muscle hyperplasia, and mucous plugging.
What role do mast cells play in asthma pathophysiology?
They release histamine, prostaglandin D2, and leukotrienes, initiating bronchoconstrictor responses.
Describe the stepwise approach to asthma therapy.
Progression from SABA as needed, low-dose ICS, ICS/LABA, to high-dose ICS and additional controllers based on severity.
What are common side effects of LABAs?
Tremors, palpitations, muscle cramps, and hypokalemia.
What dietary factors are linked to increased asthma risk?
Low intake of antioxidants, high sodium, and omega-6 fatty acids.
