Clinical meaning
Asthma is chronic inflammatory disease driven by Th2 immune response producing IL-4 (IgE switching), IL-5 (eosinophil recruitment), IL-13 (mucus, hyperresponsiveness). IgE cross-linking triggers mast cell degranulation. Stepwise therapy: Step 1-2 = PRN ICS-formoterol; Step 3 = low-dose ICS-LABA; Step 4-5 = medium-high ICS-LABA +/- LAMA +/- biologic.
Diagnosis & workup
Diagnostics & workup: - Thoracentesis with Light criteria for pleural effusion classification - Peak expiratory flow rate monitoring for asthma - Bronchoscopy with BAL for diagnostic sampling - Pulmonary function tests: FEV1, FVC, FEV1/FVC ratio, DLCO - 6-minute walk test for functional capacity assessment - Chest X-ray PA and lateral (infiltrates, hyperinflation, effusions) - Methacholine challenge for suspected asthma with normal spirometry
Risk factors: - Prematurity with bronchopulmonary dysplasia history - Age >65 with declining mucociliary clearance - Environmental allergen sensitization (dust mites, mold, pollen) - Current or former tobacco use (pack-year calculation) - Connective tissue disease with ILD predisposition - Indoor air pollution and biomass fuel exposure - Radiation therapy to chest