Invasive external otitis: review of 12 cases.

Invasive external otitis is an infection caused by Pseudomonas aeruginosa that often occurs in elderly people with diabetes. Twelve cases that illustrate the problems associated with the clinical recognition and successful outcome of the condition were reviewed. The patients' average age was 62.5 years, and they had been ill for an average of 1.8 months before admission to hospital. Predisposing factors included diabetes, swimming in a warm climate and the use of a hearing aid. Radionuclide bone scanning and surgical exploration revealed pathognomonic findings. Initial therapy was often suboptimal: one or more relapses occurred in seven of the patients. All of the patients were cured without relapse after a minimum of 4 weeks of therapy with tobramycin plus an anti-Pseudomonas penicillin. The average duration of the illness was 3.9 months. The outcome in invasive external otitis should be excellent if the condition is diagnosed early and appropriate therapy is instituted.