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
A 60-year-old diabetic patient presents with extremely painful lesion in the external ear and otorrhea not responding to antibiotics. There is evidence of granulation type tissue in the external ear and bony erosion with facial nerve palsy is noted. The most likely diagnosis is 
Select and explain. 
A. Malignant otitis externa, B. Nasopharyngeal carcinoma, C. Chronic suppurative otitis media, D. Acute suppurative otitis media
A: Malignant otitis externa
Answer: A: Malignant otitis externa 
Explanation: It is an inflammatory condition caused by Pseudomonas infection, usually in the elderly diabetics or in those on immunosuppressive drugs. Its early manifestations resemble diffuse otitis external but there is excruciating pain and appearance of granulations in the ear canal. Facial palsy is common. Infection may spread to the skull base and jugular foramen causing multiple cranial nerve palsies. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 55)