This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
Which of the organism causes malignant otitis externa? 
Select and explain. 
A. Staphylococcus aureus, B. Pseudomonas aeruginosa, C. Candida albicans, D. E. coli
B: Pseudomonas aeruginosa
Answer: B: Pseudomonas aeruginosa 
Explanation: Malignant (necrotizing) otitis externa is a paicularly aggressive life-threatening form of infection caused by Pseudomonas aeruginosa infection. It usually in the elderly diabetics, or in those on immunosuppressive drugs. Its early manifestations resemble diffuse otitis externa but there is excruciating pain and appearance of granulations in the meatus. Facial paralysis is common.