The diagnostic criteria and treatment strategies for Malignant External Otitis (MEO) and Skull-Base Osteomyelitis (SBO) have not yet been firmly established; therefore, treatment of these diseases remains a challenge in clinical practice. We present 4 cases of MEO and SBO and the results of our analysis of the data of 50 patients who were treated between 1990 and 2015 in Japan. We found that both MEO and SBO are more likely to affect the elderly, and immunodeficient patients, such as those with diabetes mellitus. The mortality rate was as high as 20%, tending to be even higher in patients with paralysis of multiple cranial nerves. In addition, we observed that SBO patients who did not exhibit any signs of inflammation in their external auditory canals were predisposed to recurrences. Thus, we conclude that long-term treatment with antibiotics and follow-up are critical, particularly for those patients who are at a high risk of these diseases.

　Hereditary Hemorrhagic Telangiectasia (HHT) is one of the causes of recurrent epistaxis. We report the case of a patient with Rendu-Osler-Weber disease who presented with severe epistaxis and was treated, in collaboration with a neurosurgeon, by superselective embolization.

　A 74-year-old male patient with HHT presented to us at Jikei University, School of Medicine, with a 7-year history of recurrent severe epistaxis. The site of bleeding was identified by the otorhinolaryngologist during angiography, and superselective embolization was performed by the neurosurgeon.
　Successful control of the recurrent epistaxis was achieved after the superselective embolization, with minimal mucosal damage of the nose.
　Endovascular treatment, especially superselective embolization, appears to be an effective treatment strategy for recurrent epistaxis in patients with HHT.

　We report a case of fixation of the ossicles after fracture of the lateral wall of the tympanic attic by ear-pick injury. A 20-year-old man presented with a 2-year history of right-sided hearing loss after an ear-pick injury. Because of a type A_D tympanogram suggesting dislocation of the ossicles, conductive hearing loss, and slight dislocation of the incus revealed by computed tomography, we suspected dislocation of the ossicles and performed tympanoplasty. However, at operation, we found that the lateral wall of the tympanic attic was fractured and that a fragment of the fracture was attached to the incus, causing the incus to lose its mobility. To the best of our knowledge, fracture of the lateral wall of the tympanic attic by ear-pick injury has not been previously reported.

　A 65-year-old male visited our hospital with a 6-months's history of left-sided hearing loss and tinnitus. He had previously been treated with prednisolone, minocycline and levofloxacin at a neighborhood otolaryngological clinic. Physical examination revealed a small perforation in his left tympanic membrane, associated with otorrhea. Laboratory examination revealed a positive test result for PR3-ANCA and mild proteinuria. On the basis of these findings, we made a presumptive diagnosis of Otitis Media with ANCA Associated Vasculitis (OMAAV). However, a plain chest X-ray and CT demonstrated cavitation in the left upper lung field, and his sputum and otorrhea fluid tested positive for M.tuberculosis by PCR. Therefore, the final diagnosis was lung and middle ear tuberculosis. As the patient lacked any other signs or symptoms of vasculitis, the positive test result for PR3-ANCA was considered to be a false-positive result. The patient was treated with rifampicin, isoniazid, pyrazinamide and ethambutol, and showed complete disease remission. Thus, it is important to rule out tuberculosis before we make the diagnosis of OMAAV.

　We report the case of a patient with eosinophilic granulomatosis with polyangiitis (EGPA), which was initially suspected to be eosinophilic otitis media. A 36-year-old woman with bronchial asthma presented with otitis media with otorrhea, and hearing loss in the right ear. Two weeks before her first visit to our department, she had received intravenous steroid treatment for acute severe asthma. Cytologic examination of the otorrhea fluid revealed no eosinophils, presumably on account of the recent systemic steroid therapy. However, the other features were consistent with the diagnosis of eosinophilic otitis media. At follow-up, she complained of numbness of the limbs and bilateral foot drop, diagnosed as being caused by mononeuritis multiplex. Peripheral blood examination revealed severe eosinophilia, and the patient was finally diagnosed as having EGPA.

　This was a case initially suspected as eosinophilic otitis media, which was finally diagnosed as EGPA. We believe that the features of EGPA may have been masked by the steroid treatment for bronchial asthma. It is important to bear in mind the possibility of EGPA, even if eosinophilic otitis media is suspected.

Key words: eosinophilic otitis media, mononeuritis multiplex, otitis media with ANCA-associated vasculitis (OMAAV), Eosinophilic Granulomatosis with Polyangiitis (EGPA)