Otitis externa malignaexperiencia a lo largo de 25 años en un hospital de tercer nivel

Zusammenfassung

Introduction and objective: Malignant external otitis (MEO) is an aggressive infection with high morbility but low mortality, of the soft tissues of the external canal and surrounding structures, which can spread and involve the skull base and the temporomandibular joint (TMJ). It mainly affects immunocompromised patients over 65 years of age, especially diabetics. It is typically caused by Pseudomona aeruginosa, and the diagnosis should be suspected in patients with typical symptoms of otalgia (predominantly nocturnal) and otorrhea that doesn’t improve despite conventional treatments. The objective of this study has been to know the characteristics of patients diagnosed with OEM in our hospital in recent years and to establish the diagnosis and therapeutic criteria for this rare disease. Method: A descriptive, observational, and retrospective study of patients diagnosed with MEO at the University Clinical Hospital (Valladolid, Spain) between 1996 and 2021 was carried out. Results: Nine patients were diagnosed with MEO in the last 25 years, 78% male (7/9), and with a mean age of 76.8±10.9 years (56-93 years). All patients manifested the disease early with otalgia, otorrhea and the presence of granulation tissue in the external auditory canal (EAC). None had cranial nerve involvement (skull base osteomyelitis), but four had TMJ invasión. Only in three of them, the culture of the EAC exudate was positive for Pseudomonas aeruginosa, confirming the great microbiological variability. Regarding treatment, all received intravenous antibiotic therapy with or without antifungal treatment, for a prolonged period of time. Only one patient underwent surgery. Two of the nine patients in the sample died. Discussion and Conclusions: In 1968 Chandler described MEO, and in 1987 Cohen and Friedman listed a set of criteria to define it. Currently the diagnosis of MEO is established from a variety of clinical, laboratory and radiographic findings. When a patient, especially a diabetic, refers otalgia or otorrhea, showing on examination an inflammation of the EAC with the presence of granulation tissue, MEO should be considered. Biopsy is essential to make the differential diagnosis between MEO and squamous cell carcinoma of the EAC. Antimicrobial therapy depends on the severity of the infection and the local rate of fluoroquinolone resistance in Pseudomonas. Initially, intravenous ciprofloxacin will be used at a dose of 400mg every 8 hours, with or without an antipseudomonal beta-lactam for 6-8 weeks. Since the availability of systemic antipseudomonal antibiotics, surgical treatment of this pathology is not indicated, performing only biopsy or debridement for differential diagnosis with tumor pathology.