[4] Asthma Flashcards
What is asthma?
A common lung condition that causes occassional breathing difficulties due to reversible airway obstruction
What happens when an environmental trigger is breathed in in asthma?
A type 1 hypersensitivity reaction occurs involving Th2 cells
What happens when a type 1 hypersensitivity reaction occurs in asthma?
Acute narrowing of the airway, and the classic symptoms of wheezing
What leads to the acute narrowing of the airway in asthma?
- Increased contractility of smooth muscle
- Mucosal swelling/inflammation
- Increased mucus production
What causes increased contractility of smooth muscle in asthma?
Chronic inflammation of the conducting zone of the airways, especially the bronchi and bronchioles
What causes mucosal swelling/inflammation in asthma?
Mast cell and basophil degranulation, resulting in the release of inflammation mediators
Is the narrowing reversible in asthma?
Yes, it is typically reversible with or without treatment, however occassionally the airways change
What long-term changes might occur in asthma?
- Increased eosinophils
- Thickening of the lamina reticularis
- Changes in size of airway smooth msucle
- Increase in number of mucous glands
What are the causes of asthma?
The exact cause of asthma is unknown, but several factors have been suggested as possible causes, including;
- Modern hygiene standards
- Air pollution
- Chlorine in swimming pools
- Genes
What are the risk factors for asthma?
- Family history of asthma or related atopic conditions
- Having another atopic condition yourself
- Having bronchiolitis as a child
- Exposure to tobacco smoke as a child
- Mother smoking during pregnancy
- Being born prematurely, or with a low birth weight
Give 3 examples of atopic conditions that might be associated with asthma
- Eczema
- Food allergy
- Hay fever
What is bronchiolitis?
A common lower respiratory tract infection that affects babies and young children under the age of 2
How serious is bronchiolitis?
Most cases are mild, and clear up without the need for treatment within 2-3 weeks, although some children have severe symptoms and require hospitalisation
What causes bronchiolitis?
RSV, which causes the bronchioles to become inflamed, reducing air entry into the lungs and making it difficult to breathe
What are the early symptoms of bronchiolitis?
Those of a common cold, including runny nose and cough
What symptoms develop over a few days in bronchiolitis?
- Fever
- Dry and persistent cough
- Difficulty feeding
- Wheezing
Is there any effective anti-viral for bronchiolitis?
No
How is bronchiolitis treated?
Treatment is supporive, including ensuring sufficient fluid intake, and paracetamol or ibuprofen for pain relief
What occupations are at risk of asthma?
- Paint sprayers
- Bakers and pastry makers
- Nurses
- Chemical workers
- Animal handlers
- Welders
- Food processing workers
- Timber workers
What are the potential triggers for asthma?
- Infections
- Allergens
- Airborne irritants
- Medicines
- Emotions
- Food additives
- Weather conditions
- Mold or damp
- Exercise
- Food allergies
What infections in particular can trigger asthma?
Those of the upper airway
Give 3 example of allergens that can trigger asthma
- Pollen
- Dust mites
- Animal fur
Give 3 airborne irritants that might trigger asthma
- Cigarette smoke
- Fumes
- Pollution
What medicines in particular can trigger asthma?
NSAIDs