Endocrine Abstracts

Introduction: Malignant or necrotizing external otitis (MEO) is an invasive infection between external auditory canal and skull base. It is more frequent in elderly and in diabetic patients or with compromised immune system. As MEO advance osteomyelitis can developed. It is a severe and potential mortal complication of external otitis (EO).

Clinical case: 78 years old man with history of type2 diabetes (good metabolic control) and right ear external otitis. In May 2019 initiate topic ofloxacin after diagnosis of EO. After 15 days he is admitted in emergency department (ED) with persistent otalgia in spite of treatment and was hospitalized on suspicious of MEO for IV antibiotic treatment. Analytically showed leucocytosis, elevated erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP), glycemia 224 mg/dl and HbA1c 6.4%. Cultural auricular exudate: staphylococus epidermidis, only sensible for gentamicin, ciprofloxacin and vancomycin. Computed tomography (CT) revealed right media osteomyelitis that was confirmed by technetium scanning. Started ciprofloxacin iv 400 mg with clinical and analytical improvement and was discharged with oral ciprofloxacin and ofloxacin up to 8 weeks of total treatment. Four months later returns to ER complaining with severe otalgia with retro-auricle irradiation in RE. Right otoscopy with mesotympanic perforation without otorrhea, and painful pre and retro-auricle palpation. He has elevated both ESR and CRP. Skull base osteomyelitis recurrence was admitted, being hospitalized under iv ciprofloxacin 400 mg. Cultural auricular exudate isolated a multi-resistant Klebsiella pneumoniae spp only sensible for ertapenem. Antibiotic was adjusted, with clinical and analytical improvement. Gallium citrate scanning evidenced favourable evolution maintaining active inflammation. Patient is clinically improved maintaining follow-up in endocrine and otorhinolaryngology consultation.

Discussion: This case resumes a potential and severe complication present in elderly with diabetes. This group of patients are in major risk of developing this condition because macroangiopathic alterations in ear, increased pH of cerumen and phagocytic dysfunction of leucocytes from diabetes. Metabolic control of diabetes is not a risk factor for developing MEO but it is important for treatment success. Not as frequent as pseudomonas aeruginosa, colonization by klebsiella pneumoniae spp (8–19%) or commensal bacteria staphylococus epidermidis (4–9%) are described in the literature. Suspicion and alert for this pathology allows for successful diagnosis and opportune treatment.