210 Asthma Flashcards
What is extrinsic asthma?
Most common form of asthma - IgE mediated hypersensitivity reaction and usually develops in children <10
What is intrinsic asthma?
Less common than extrinsic with no extrinsic cause - develops in later life and less responsive to treatment and more progressive
What are the 3 major characteristics of asthma?
- Airway narrowing
- Increased sensitivity to bronchoconstricting stimuli
- Increased inflammatory cell no in the bronchioles
How long does the early response in asthma last?
Develops in minutes and subsides within ~2 hours
What is a type 1 hypersensitivity reaction in asthma?
mention mast cells; histamine; IL-5
- antigen crosslinking with IgE on mast cells causing degranulation
- histamine and prostaglandins and leukotrienes cause from the degranulation cause bronchoconstriction; increased mucous; microvascular leakage
- IL-5 encourages eosinophilic recruitment
What should be given as treatment for late response asthma?
Corticosteroids as less responsive to B2 agonists
Which cells cause diffuse inflammation in late response asthma?
Eosinophils but also: Th2, B cells, macrophages, basophils
What is the result of immune cell mediated diffuse inflammation in asthma?
Airway inflammation; oedema; mucous plugs; hyper-responsiveness and bronchoconstriction (due to SNS stimulation)
What is the long term damage in asthma?
Bronchial wall thickening (collagen deposition)
SM and goblet cell hypertrophy
Epithelial loss
What 5 investigations can be performed to diagnose asthma?
- PEFR
- Spirometry
- Methacholine challenge
- Skin prick testing (allergy)
- Excercise test (useful in children)
What pattern does asthma show in spirometry?
Obstructive i.e. decreased FEV1: FVC ratio
Name the 6 pharmacological treatment of asthma
- B2 agonists
- ICS
- LABAs
- Leukotrienes
- Xanthines
- Biologics
Give 1 example of an ICS (used in the Tx of asthma)
Beclometasone
Fluticasone
Budesomide
Give 1 example of a LABA (used in the Tx of asthma)
Salmeterol
Formeterol
Give 1 example of a leukotriene receptor antagonist (used in the Tx of asthma)
Montelukast
Give 1 example of a Xanthine (used in the Tx of asthma)
Theophylline
Aminophylline
Give 1 example of a biologic used in the Tx of asthma
Omaluzimab
What is treatment for intermittent asthma?
No controller
What is the treatment for mild persistent asthma?
Low dose ICS
What is the treatment for moderate persistent asthma?
Low to medium dose of ICS + LABA
What is the treatment for severe persistent asthma
High dose ICS + LABA +/- other drugs
Which group of drugs should be avoided in asthma?
NSAIDs - block COX-2 inhibition which catalyses arachodonic acid –> thromboxane which causes further bronchoconstriction
What are the 3 red flags of acute asthma?
Cyanosis
Silent chest
Lack of distress
What investigations should be performed in severe asthma attack?
(5 listed)
ABG CXR - to exclude PnTx, infection etc Bloods Blood culture Sputum cultures
