難治性中耳炎の取り扱い

In daily practice, acute otitis media and otitis media with effusion are usually treated by administration of antibacterial drugs, tympanostomy and insertion of tympanic membrane ventilation tubes. Most inflammatory diseases of the middle and external ear canal are caused by microorganisms such as bacteria and fungi, and identifying the causative microorganisms and selecting appropriate antibacterial and antifungal agents is important. If treatment is unsuccessful despite appropriate therapy, the possibility of other specific non-infectious inflammatory diseases should be considered. Otitis media with ANCA-associated vasculitis (OMAAV) is one of the intractable types of otitis media that does not respond satisfactorily to conventional treatments. OMAAV is caused by systemic microangiitis and is characterized by positive serology for anti-neutrophil cytoplasmic antibodies. Awareness of this disease in the clinical setting has increased after the diagnostic criteria for OMAAV were published in 2015. In this review, I shall provide an overview of OMAAV and discuss the diseases that should be differentiated from OMAAV. The causes of intractable otorrhea are not limited to otitis media, but also include external ear diseases, such as otitis externa and fungal infections of the external auditory canal, inflammatory diseases with morphological abnormalities, such as middle ear cholesteatoma, as well as cancer of the external auditory canal and skull-base osteomyelitis, in which inflammation spreads to the bone marrow. On the other hand, the possibility of OMAAV should also be considered in cases of prolonged otitis media with effusion without otorrhea, especially when impaired bone-conduction hearing, progressive hearing loss, and particular tympanic membrane findings are seen. It is important to make the diagnosis based on the presence or absence of findings characteristic of each disease. If the symptoms do not improve or are recurrent, a judgement needs to be made about whether the current diagnosis is consistent or another causative disease needs to be considered.