Both clinical and basic research for chronic rhinosinusitis with nasal polyps (CRSwNP) have been done worldwide. It has been considered that eosinophilic-dominant and enhanced type 2 inflammation in NPs are major factors that are related to the recurrence of NPs. Several reports recently revealed that that gene expression pattern in NPs may affect its recurrence; however, the crucial genes that affect the recurrence of NPs, except for type 2 cytokines, are not well-understood. In Japan, the diagnostic criteria for eosinophilic chronic rhinosinusitis (ECRS) have been established. Furthermore, it has been reported that there are several different gene expression patterns between ECRS and non-ECRS cases. Among them, ALOX15, which encodes for 15-lipoxygenase-1 (15-LOX-1) and has an important role in the inflammatory process, was found to be elevated in NPs of patients with ECRS. According to several recent reports on ALOX15, ALOX15 may be a candidate gene that affects the formation and recurrence of NPs. Although several lipid mediators generated by 15-LOX-1 contain both pro- and anti-inflammatory functions, the significance and regulation of 15-LOX-1 in NPs are not well-understood. Herein, we discuss the function and regulation of 15-LOX-1 in NPs.

Deep neck abscess is a life-threatening disease that results in the formation of abscess within neck spaces due to bacterial infection in tonsils, mandibular teeth, or salivary glands. A retrospective study was conducted using the data on 33 patients diagnosed with the deep neck abscess (25 males and 8 females; age range, 0–99 years; median, 61 years) between 2010 and 2020. The median duration from the onset of symptoms to the first visit was 3 days (range, 1–7 days). Five of 33 (15.2%) patients had diabetes. The median white blood cell count and serum C-reactive protein level on day 1 of hospitalization were 13,940/μl (range, 7,100–34,670/μl) and 18.37 mg/dl (range, 1.26–36.5 mg/dl), respectively. Computed tomography (CT) revealed neck abscess involved in six or more spaces in eight (24.2%) patients and extension into the neck spaces under the hyoid bone in 21 (63.6%) patients. A total of 13 (39.3%) patients with severe laryngeal edema required tracheotomy. Bacterial examination of pus obtained from the abscess indicated the presence of both Streptococcus anginosus group (SAG) and anaerobic bacteria in 14 (42.4%) patients. The number of patients with extension of abscess into the neck spaces under the hyoid bone, neck abscess in six or more spaces, and the presence of both SAG and anaerobic bacteria was significantly higher in the tracheostomy group (p=0.004, p=0.005, and p=0.007, respectively). The number of patients with extension of abscess into the neck spaces under the hyoid bone, and the presence of both SAG and anaerobic bacteria were significantly correlated with the longer duration of hospitalization (p=0.02, and p=0.02, respectively). These results indicated that evaluation of the involved spaces using CT and detection of SAG and anaerobic bacteria could contribute to the extension of hospitalization.

Background: Impaired olfaction is one of the characteristic symptoms of coronavirus disease (COVID-19). The olfactory cleft of COVID-19 patients with olfactory dysfunction reportedly appears closed on sinus computed tomography (CT). However, the etiology of olfactory cleft obstruction in these patients, including its frequency, severity, and mechanism, has not been fully elucidated. This study investigated the relationship between the olfactory dysfunction and olfactory cleft obstruction in COVID-19 patients.

Methods: Among the COVID-19 patients treated at our hospital between April 2020 and January 2021, this study included 91 patients who underwent sinus CT examination. The data on the presence or absence of olfactory dysfunction was collected retrospectively from electronic medical records. Olfactory cleft obstruction was scored on a scale of 0–4, depending on the degree of obstruction. In patients with olfactory dysfunction, changes over time were evaluated using the visual analogue scale (VAS), self-administered odor questionnaire, open essence test, and CT score of the olfactory cleft.

Results: Olfactory dysfunction was noted in 15 patients (16.5%). The CT score was significantly higher in patients with olfactory dysfunction than in those without, and the olfactory cleft tended to be closed in the former. The overall and perfume-related olfactory VAS scores, open-essence test, and CT scores improved significantly over time. There was a correlation between the changes in the olfactory dysfunction and changes in the CT scores.

Conclusions: COVID-19 patients with olfactory dysfunction showed significant olfactory cleft obstruction on sinus CT, which could prevent the improvement of olfactory dysfunction in them.

Epiglottic abscess is one of the complications of acute epiglottitis. As it can expand and cause obstruction of the upper airway, we must always take tracheostomy and abscess drainage under consideration. Although the condition is rare, here, we report a case of epiglottic abscess caused by gas-forming bacteria. A man in his fifties presented with a three-day history of progressive sore throat. Fiberoptic laryngoscopy revealed a yellow colored epiglottic swelling. Antibiotics were administered; however, the swelling of the right arytenoid progressed. In addition, CT showed gas in the epiglottis. We performed surgical drainage and tracheostomy. The abscess resolved, and the patient was discharged from the hospital on the tenth day from admission.

Eosinophilic chronic rhinosinusitis (ECRS) is often associated with asthma and serves as a risk factor for frequent asthma exacerbation. Recent studies have reported the usefulness of biologics for management of ECRS and asthma in patients who are unresponsive to oral steroids.

A man in his 70s was diagnosed with aspirin-induced asthma and chronic obstructive pulmonary disease approximately 5 years prior to presentation. Mepolizumab therapy was initiated owing to unresponsiveness to treatment including oral steroid administration. Asthma attacks reduced in frequency; however, oral steroids could not be withdrawn. The patient developed nasal symptoms following a 28-month course of mepolizumab therapy, which was therefore switched to dupilumab to improve sinusitis and asthma. The patient was diagnosed with severe ECRS based on a Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis score of 15, asthma, and biopsy proven evidence of nasal polyps. Nasal symptoms, except for olfactory dysfunction and sinusitis improved following 7-month dupilumab treatment; however, lung dysfunction and asthma persisted.

Close interdisciplinary collaboration between Respiratory Medicine and Otorhinolaryngology is essential for accurate evaluation and treatment of patients with dissimilar responsiveness of the upper and lower respiratory tracts to treatment with the aforementioned medications.