This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
7.Rhinoscleromatis is caused by: 
Select and explain. 
A. Klebsiella, B. Autoimmune, C. Spirochetes, D. Rhinosporidium
A: Klebsiella
Answer: A: Klebsiella 
Explanation: . Rhinoscleroma is caused by a Gram-negative cocco-bacillus Klebsiella rhinoscleromatis. The diseases passes through three stages--catarrhal, granulomatous and cicatricial. It causes woody infiltration of the upper lip. Other areas involved are larynx (subglottic region) and trachea leading to airway obstruction. Mikulicz cells and Russell bodies are characteristically seen on histology. Ref: Dhingra 7e pg 175.