This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hypersensitivity, Subject name: Pathology
Which of the following is not a feature of bronchial asthma? 
Select and explain. 
A. Thickening of bronchial wall, B. Increase in number of airway goblet cells, C. Fibroblastic foci, D. Sub-basement membrane fibrosis
C: Fibroblastic foci
Answer: C: Fibroblastic foci 
Explanation: Fibroblastic foci (exuberant proliferation of fibroblasts) is a feature of idiopathic pulmonary fibrosis (IPF). Bronchial asthma is an example of Type I Hypersensitivity reaction and is characterised by airway remodeling which includes: Thickening of bronchial wall with hyperophy and/or hyperplasia of bronchial smooth muscles Increase in size of submucosal glands and number of goblet cells Increased vascularity Sub-basement membrane fibrosis (due to deposition of type I and III collagens) Key points - Sputum findings in bronchial asthma: Curshmann spirals - impacted mucin plugs Charcot Leyden crystals - Eosinophil crushing aefact Creola bodies - damaged respiratory epithelial cells