Malignant otitis externa is defined as rapidly progressive infection of external auditory meatus spreading to surrounding soft tissues and bones of skull base Malignant is a misnomer (Chandler 1968): Aggressive clinical behavior, poor treatment outcome and high mortality in elderly uncontrolled diabetics Synonyms : Invasive/ granulomatous/ necrotizing otitis externa Skull base osteomyelitis Predisposing factors Elderly , poorly controlled diabetics, prolonged steroid use, atherosclerosis, immunosuppressed, AIDS Causative organisms Pseudomonas aeruginosa (95%) Staph. epidermidis Aspergillus fumigatus Hallmark of disease Granulation tissue at the junction of cartilaginous and bony EAC