[Otitis externa maligna and cranial neuropathy]

Malignant external otitis (MEO) is a disease of the external auditive channel (EAC) due to Pseudomonas aeruginosa which usually involves individuals with diabetes mellitus. It may result in the invasion of the cranial base with cranial neuropathy and a high mortality rate despite therapy. We report the clinical features, diagnostic procedures, evolution and therapy of 8 patients with MEO, seven of which had cranial neuropathy. All patients have diabetes except one who had acquired immunodeficiency syndrome. All had otalgia, otorrhea and headache lasting for several months. Six patients had homolateral (as related to the MEO) facial palsy. One patient with bilateral MEO developed bilateral facial palsy and lesion of the cranial nerves VI (unilaterally) and IX through XII (bilaterally). In all patients P. aeruginosa was cultured from the EAC exudate scintigraphy with 99Tc showed uptake at medium ear and mastoid level in all 8 patients, suggesting a possible osteomyelitis. Scintigraphy with 67Ga was positive in the 6 cases where it was carried out, showing uptake in the soft tissues of the cranial base. Computed tomography was carried out in 6 patients, and it was useful to define the anatomical extent of the disease. The patients received different therapeutic schedules, particularly the combination of a betalactamic and aminoglucoside antibiotics. Follow up was characterized by common recurrences, and one patient died. The importance of early diagnosis and treatment to prevent the extension and recurrence of MEO are discussed. Cranial neuropathy is considered as a poor prognostic finding.