Asthma is a heterogeneous disease, characterized by chronic airway inflammation. It is defined by h/o respiratory symptoms such as dry cough, SOB, chest tightness, a wheeze that vary over time & intensity, together with variable expiratory airway limitation, which may later become persistent.
In common language, asthma is associated with airway hyper-responsiveness and airway inflammation in response to an external allergen; which leads to airway narrowing & subsequently difficulty in breathing.
Epidemiology:
- As of 2004, it was estimated that as many as 300 million people of all ages suffer from asthma, by 2025, it is expected that this number will rise to 400 million worldwide (GINA).
- The Indian study on the epidemiology of asthma.
- Respiratory symptoms and chronic bronchitis (INSEARCH) in every adult, estimated the prevalence rate of asthma at 2.05% between 2007 and 2009, with an estimated burden of about 17.23 million in 2011.
- Agarwal etal. estimated the prevalence rate of self-reported asthma at around 2%.
Asthma phenotypes: Recognizable cluster of demographic, clinical, and/or pathophysiological characteristics are k/an asthma phenotype.
- Allergic asthma
- Non-allergic asthma
- Adult-onset (late-onset) asthma
- Asthma with persistent airflow limitation
- Asthma with obesity
Triggering factors:
- Respiratory infection (viral)
- Allergen or irritant exposure
- Cold weather
- Exercise
- Smoke/dust/fumes
- Medication such as B-blocker (beta-blocker) and aspirin
- Pollen
- Mites
- Mould & fungus
- Air pollutants (NO2, SO2, O3)
- Emotional stress
Diagnosis of Bronchial Asthma:
- History of variable respiratory symptoms:
- Wheeze
- SOB (shortness of breath)
- Chest tightness
- Cough
Pulmonary function test with bronchodilator reversibility:
- Document variable expiratory airflow limitation.
- At a time when fevi is reduced, confirm that fevi/fvc is also reduced.
- Positive BDR: increase in FEV, >12% and >200 ml from baseline.
Management:
1. Non-pharmacological:
- Cersation of smoking & ETS (Environmental Tobacco smoke exposure)
- Encourage regular physical activity for general health benefits
- Avoid medication (NSAIDs; beta-blocker)
- Weight reduction/healthy diet
- Encourage breathing exercises
- Avoid outdoor allergen (like pollen/dust)
- Deal with emotional stress (anxiety/depression)
- Psychological counseling.
2. Pharmacological:
- Inhaled coticosteroid
- Inhaled long-acting beta-agonist
- Leukotriene modifiers
Add on therapy:
- Tiotropium
- Low dose Macrolide
- Low dose oral corticosteroid
- Anti IgE
- Anti IL4 R
- Anti IL5/5R
- Bronchial Thermoplasty
Other Therapies:
- Allergen Immunotherapy
- Vaccination – Influenza & Pneumococcal Vaccine
- Vitamin D Supplementation
Dr. Jagdish Lohia, Consultant – Pulmonology, Brahmananda Narayana Multispeciality Hospital, Jamshedpur