This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
Blue eardrum is seen in 
Select and explain. 
A. Serous otitis media, B. CSOM, C. Perforation, D. None
A: Serous otitis media
Answer: A: Serous otitis media 
Explanation: Serous otitis media is an insidious condition characterized by an accumulation of nonpurulent effusion in the middle ear cleft. In otoscopy, the tympanic membrane is often dull and opaque with loss of the light reflex. It may appear yellow, grey or bluish in colour. Reference: Diseases of Ear, Nose and Throat, PL Dhingra, Shruthi Dhingra,7th edition, pg no.69