A 55 year old male, who is a known case of severe persistent asthma since 14 years of age presents with acute exacerbation of asthma. The disease was well controlled upto 54 years with high dose inhaled corticosteroids. For the past 12 months the disease was not in good control. He complains of nocturnal cough, limitation of daily activities in spite of good compliance with medications. Spirometry was suggestive of bronchial asthma with partial irreversibility of airway obstruction. What is the cause for poor disease control?

Answer: c) Airway remodeling (HARRISON 19TH ED, P-1675; ROBBINS 9TH ED, P-682)Airway remodeling:Over time, repeated bouts of allergen exposure and immune reactions result in structural changes in the bronchial wall, referred to as "airway remodeling"Airway remodeling adds an irreversible component to the obstructive disease The characteristic histological findings called 'airway remodeling' consists ofThickening of airway wallSub-basement membrane fibrosisBronchial epithelial basement membrane thickeningIncreased vascularityIncrease in size of submucosal glands and number of airway goblet cellsHypertrophy and/or hyperplasia of bronchial wall muscle