The pathogenesis of allergic rhinitis is associated with genetic, environmental, and epigenetic factors. Genotyping of single nucleotide polymorphisms (SNPs) is an advanced technique in the field of molecular genetics that is closely correlated with genome-wide association studies (GWASs) in large population groups with allergic diseases. Many recent studies have paid attention to the role of epigenetics, including alteration of DNA methylation, histone acetylation, and miRNA levels in the pathogenesis of allergic rhinitis. In this review article, genetics and epigenetics of allergic rhinitis, including information regarding functions and significance of previously known and newly-discovered genes, are summarized. Directions for future genetic and epigenetic studies of allergic rhinitis are also proposed.

Objectives. Postinfectious olfactory dysfunction (PIOD) is the most common etiology of olfactory dysfunction, and olfactory training (OT) is an accepted treatment modality for PIOD. Some studies have investigated OT in Korean patients, but they involved odorants unfamiliar to Koreans or had no control group. The aim of this study was to verify the efficacy of OT in PIOD patients, using odorants familiar to Koreans and including a control group.Methods. We enrolled a total of 104 Korean patients with PIOD over the 3-year study period. All participants were assessed using endoscopy and an olfactory function test at the baseline assessment and 3 months after OT. The olfactory function test was performed using the Korean version of Sniffin’ stick (KVSS) II. Nasal and psychological function was evaluated using a visual analog scale and the Mini-Mental State Examination. OT was performed over a period of 3 months, using five odorants (rose, lemon, cinnamon, orange, and peach).Results. OT improved olfactory function in approximately 40% of subjects over a period of 12 weeks compared to non-OT subjects. A comparison of changes between the initial and follow-up assessments demonstrated that the OT group had significantly better olfactory results for the total KVSS II, threshold, and identification scores than the non-OT group. The degree of olfactory improvement after OT was affected by the initial score.Conclusion. The effects of OT in patients with PIOD were demonstrated in this study. A meaningful contribution of this study is that Korean patients were tested using odors familiar to them in comparison with a control group.

Stamm's S-point is gaining importance as a bleeding focus in severe epistaxis. However, prevalence and features of S-point bleeding compared to non S-point bleeding have not been studied. To investigate the characteristics of patients with S-point bleeding among those with severe epistaxis and to compare the factors involved in the treatment of epistaxis. We retrospectively analyzed medical records of 268 patients admitted to the otorhinolaryngology department of Konkuk University Hospital and Chung-Ang University Hospital with epistaxis of which the bleeding focus clarified. Patients with anterior nasal bleeding (n=129) were excluded. The study was conducted at the department of otorhinolaryngology from January 2008 to August 2019. Collected data included patients' demographic information, bleeding focus, body mass index underlying medical and sinonasal diseases, laboratory test results (initial hemoglobin, platelet count, and triglyceride level), use of anticoagulants, direction of epistaxis, initial and final treatments, and need for blood transfusion. The prevalence of S-point bleeding was 28.8% of non-anterior bleeding cases. Mean body mass index score was lower in the S-point group (23.41±3.71) compared to the non S-point group (24.93±3.97) (p=0.039). Underweight patients tended to show a greater incidence of S-point bleeding (15.0%) than non S-point bleeding (2.0%) (p=0.010). Incidence of anemia was higher in the S-point group (67.5%) than in the non S-point group (36.4%). Anemia (Odds ratio [OR]: 3.635; 95% confidence interval [CI]: 1.669-7.914, p=0.001) and underweight (body mass index<18.5, OR: 8.559, CI: 1.648-44.445, p=0.011) were significantly associated with S-point bleeding. Prevalence of S-point bleeding was significant, underlining the importance of examining the S-point in patients with severe epistaxis. Patients with S-point bleeding had lower body mass index scores and a higher incidence of anemia than those with non S-point bleeding.

Olfactory disorders one of the most frequent distinctive symptoms of COVID-19 infection. COVID-19-induced olfactory disorder can be classified as post-infectious olfactory dysfunction (PIOD). The effect of drugs on olfactory disorder following upper respiratory infection, including PIOD, has not been clearly established, which adds to the difficulty with treating the disorder. However, the effect of olfactory training on PIOD has been confirmed by numerous studies. As such, olfactory training is gaining attention, and has taken on greater importance, as the sole treatment for COVID-19–induced olfactory disorder in this pandemic age. This review describes the effect of olfactory training for COVID-19–induced olfactory disorder by analyzing the relevant literature.

Objectives: Olfactory dysfunction is a common complaint in patients with chronic rhinosinusitis (CRS). The study aimed to evaluate the effectiveness of olfactory training (OT) in patients with CRS after sinonasal surgery.Methods: We enrolled 111 patients with CRS who underwent sinonasal surgery. Prior to surgery and 3 months after starting OT, the participants were assessed by both an olfactory function test and endoscopy. The Korean version of the Sniffin' Stick II (KVSS‐II) was used to perform the olfactory function test. Over the course of 3 months, five odorants were used in OT (rose, lemon, cinnamon, orange, and peach).Results: Over a 12‐week duration, 37% of the participants in the OT group showed clinically relevant increase in olfactory function. The OT group had significantly higher olfactory outcomes for the total KVSS‐II and identification scores than the non‐OT group between the initial and follow‐up assessments. The initial score influenced the degree of olfactory improvement after OT.Conclusions: Patients with OT exhibited significantly higher total KVSS‐II scores compared with non‐OT patients following sinonasal surgery; in particular, the odor identification score was different between the two groups. The results of this study demonstrated that a 12‐week period of repeated short‐term exposure to various odors could be useful in enhancing olfactory activity in patients who underwent sinonasal surgery for the improvement of sensory‐neural olfactory impairment.Level of evidence: 2c.

Objectives. Past several studies have proven that caffeine facilitates attentional enhancement by acting as an adenosine antagonist once it is absorbed by the body, resulting in improved psycho-behavioral function. Modern clinical olfactory function tests are usually assessed by psychophysical tests but due to a paucity of data, the influence of enhanced attention by caffeine on olfactory function still remains unclear. The objective of this study was to compare results of cognitive function (attention) and olfactory function before and after caffeine administration in order to analyze effects of caffeine on olfactory function in normosmic subjects.Methods. This study enrolled 49 participants of Konkuk University Hospital with a mean age of 27.7 years who had patent olfactory clefts and no olfactory dysfunction from May 2015 to February 2016. Subjects were restrained from caffeine 10 hours before the test. On day 1, participant’s subjective olfactory function was evaluated before and after uptake of either caffeinated or decaffeinated coffee using visual analog scale (VAS) score, minimum cross-sectional area (MCA) measured by acoustic rhinometry, and the Korean version of Sniffin’ Stick II (KVSS II). Evaluation of participant’s attentional degree was measured by d2 test. On day 2, the same procedure was carried out with counterpart substance. The type of coffee initially administrated was randomly selected.Results. After administration, caffeinated coffee resulted in significant attentional enhancement than decaffeinated coffee. Results of d2 test showed statistically significant differences in the parameters of total number of errors and omission errors. In both the caffeinated and decaffeinated groups, the patients showed slight increase in VAS score and nasal cavity area; however, the difference was not statistically significant. Also, caffeinated coffee intake compared to decaffeinated coffee intake showed no significant relevance to olfactory function.Conclusion. Caffeine may significantly improve attentional congnitive function, while not have acute effects on olfactory function.