Asthma
Also called: Bronchial asthma
Long-term inflammation makes the airways over-sensitive. Triggers cause the airway muscles to tighten and the lining to swell and produce mucus, leading to wheeze, cough and breathlessness that come and go.
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About 260 million people worldwide; the most common chronic disease of childhood.
What happens in the body
Type-2 (eosinophilic) inflammation in most people: allergens trigger IgE, mast cells and eosinophils, causing bronchoconstriction, mucus and airway remodelling. The narrowing is largely reversible.
Causes
- Genetic predisposition combined with environmental exposures
Risk factors
- Family history of asthma or allergy
- Eczema and hay fever (atopy)
- Childhood respiratory infections
- Smoking or second-hand smoke
- Obesity
- Occupational exposures (flour, isocyanates, animals)
- Air pollution
Symptoms
- Wheeze
- Breathlessness
- Chest tightness
- Cough, often worse at night or early morning
- Symptoms triggered by exercise, cold air, allergens, infections or smoke
Diagnosis — tests and examinations
- Spirometry with reversibility testing
- Peak-flow variability diary
- FeNO (exhaled nitric oxide)
- Blood eosinophils and allergy tests
- Bronchial challenge testing if uncertain
Treatment
Medicines and medical treatment
- Inhaled corticosteroid as the foundation of treatment
- Combined budesonide–formoterol inhaler used both daily and as reliever (MART) in many guidelines
- Short-acting reliever (salbutamol)
- Add-ons: long-acting bronchodilators, leukotriene antagonists, tiotropium
- Biologics for severe eosinophilic asthma (mepolizumab, benralizumab, dupilumab, omalizumab, tezepelumab)
- Oral steroids for attacks
Operations and procedures
- Bronchial thermoplasty in selected severe cases
Self-care, home remedies and lifestyle
- Use a written asthma action plan
- Learn correct inhaler technique (spacer helps)
- Avoid known triggers and smoke
- Annual flu vaccination
- Stay active — well-controlled asthma should not limit exercise
Possible complications
- Severe attacks (status asthmaticus)
- Permanent airway remodelling
- Side effects of repeated oral steroids
- Death in poorly controlled asthma
Prevention
- Avoid smoking in pregnancy and around children
- Reduce allergen and occupational exposure
Outlook
Most people achieve full control with regular preventer treatment; many children improve in adolescence.
When to see a doctor
Seek emergency care if a reliever does not help, you cannot speak in sentences, lips turn blue or you feel drowsy.
Sources and further reading
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