Asthma Flashcards
What are the 5 defining characteristics of asthma?
Chronic Inflammatory Process Susceptibility Variable airflow obstruction Airway hyper-responsiveness Reversibility
Asthma is a chronic inflammatory process driven by what?
TH2 cells - release cytokines that activate mast cells, eosinophils and B cells which produce IgE
What type of hypersensitivity is the immediate response of asthma an example of?
Type 1 hypersensitivity
What does the immediate response of asthma lead to?
Mast cell degranulation and release of mediators (eg histamine) which cause bronchial muscle contraction and therefore bronchoconstriction
What type of hypersensitivity is the late phase response of asthma an example of?
Type IV hypersensitivity
What does the late phase response of asthma cause?
Airway inflammation
The airway inflammation seen in asthma leads to airway narrowing due to what?
- Mucosal oedema
- Thickening of bronchial walls
- Over production of mucous
- Smooth muscle contraction
Long term poorly controlled asthma can lead to airway remodelling some of which may not be fully reversible. What does the changes include?
Hypertrophy & hyperplasia of smooth muscle,
Hypertrophy of mucus glands
Thickening of the basement membrane
What pattern is seen on spirometry in an asthmatic patient?
Obstructive
What is the FEV/FVC ratio of someone who has asthma like?
Decreased, less than 70%
Name some asthma triggers
Allergens, cold air, perfumes, fumes, NSAIDS, beta blockers
Name a short acting b2 agonist
Salbutamol
How can eosinophilic inflammation be measured?
FBC, induced sputum
What are some signs and symptoms of asthma?
Expiratory wheeze, cough, difficulty breathing, chest tightness
What are the differences in the cough of a patient with COPD and a patient with asthma?
COPD - persistent, productive cough
Asthma - intermittent, usually non productive
