Malignant external otitis: a severe form of otitis in diabetic patients.

Two cases of malignant external otitis are presented and the literature is reviewed. The disease seems to occur exclusively in elderly diabetic patients. Diagnosis is mostly a clinical one, and requires a high index of suspicion. The characteristic clinical manifestations are pain and severe tenderness of the tissues around the ear and mastoid, persistent drainage and the presence of granulation tissue at the junction of the osseus and cartilagenous portions of the external ear. Roentgenographic findings are not helpful in the early stages. The pathogenesis of this disease depends on the presence of clefts in the cartilage forming the floor of the external auditory canal at its junction with the osseus portion through which infection can spread from the external ear to the deep soft tissues. Serious and often fatal complications may ensue. The most common and earliest symptom to appear if facial nerve palsy. Pseudomonas aeruginosa has been isolated uniformly, in pure or mixed cultures. This entity, therefore, should be borne in mind whenever an elderly diabetic patient presents with external otitis not amenable to the usual methods of therapy. Ps. aeruginosa should be strongly suspected, and its isolation should prompt vigorous systemic treatment with gentamicin and carbenicillin before extensive necrosis of cartilage and bone takes place. Any delay in diagnosis and management will lead to a serious and often fatal complications.