The hygiene hypothesis, first proposed in 1989, suggested that reduced exposure to infections in early life leads to allergic diseases by the defects in the establishment of immune tolerance. Although many studies provided evidence that some exposure conditions, including family size, antibiotics, probiotics, and viral or bacterial infections, are strongly related to the prevalence of allergic diseases, thereby supporting the hygiene hypothesis, some evidence does not provide acceptable results for the hygiene hypothesis. Further, most studies have focused on patients with asthma or atopic dermatitis, not allergic rhinitis. In this review, we summarize the recent studies for and against the ‘hygiene hypothesis’ and identify causal association with the prevalence of allergic rhinitis.

Background/Aims: Fexuprazan is a novel potassium-competitive acid blocker that could be of benefit to patients with gastric mucosal injury. The aim of this study was to assess the 2-week efficacy and safety of fexuprazan in patients with acute or chronic gastritis. Methods: In this study, 327 patients with acute or chronic gastritis who had one or more gastric erosions on endoscopy and subjective symptoms were randomized into three groups receiving fexuprazan 20 mg once a day (q.d.), fexuprazan 10 mg twice a day (b.i.d.), or placebo for 2 weeks. The posttreatment assessments were the primary endpoint (erosion improvement rate), secondary endpoints (cure rates of erosion and edema and improvement rates of redness, hemorrhage, and subjective symptoms), and drug-related adverse events. Results: Among the patients, 57.8% (59/102), 65.7% (67/102), and 40.6% (39/96) showed erosion improvement 2 weeks after receiving fexuprazan 20 mg q.d., fexuprazan 10 mg b.i.d., and placebo, respectively. Both fexuprazan 20 mg q.d. and 10 mg b.i.d. showed superior efficacy to the placebo (p=0.017 and p<0.001, respectively). Likewise, both fexuprazan 20 mg q.d. and 10 mg b.i.d. also showed higher erosion healing rates than the placebo (p=0.033 and p=0.010, respectively). No difference was noted in the edema healing rate and the improvement rates for redness, hemorrhage, and subjective symptoms between the fexuprazan and placebo groups.No significant difference was noted in the incidence of adverse drug reactions. Conclusions Fexuprazan 20 mg q.d. and 10 mg b.i.d. for 2 weeks showed therapeutic efficacy superior to that of placebo in patients with acute or chronic gastritis (ClinicalTrials.gov identifier NCT04341454).

Allergic rhinitis (AR) is a type of rhinitis accompanied by sensitization to allergens. One of the most clinically important allergens is pollen. Recently, due to climate change and CO 2 air pollution, the flowering period starts earlier and persists longer. In addition, antigenicity due to environmental pollution is also being strengthened. As a result, the sensitization rate to pollen antigens is on the rise. It is known that the prevalence of AR especially caused by pollen is rapidly escalating. Although the causal relationship between pollen exposure and the severity of rhinitis is not precisely established, an association of rhinitis symptoms with the time of pollen scattering exists. In addition, the mixed effect of environmental pollution and pollen may play a role in the development of rhinitis symptoms. Therefore, in order to avoid pollen, it is necessary to constantly improve pollen forecast and minimize the contact with pollen indoors and outdoors. Treatment of AR should be performed according to guidelines. Also, continuous efforts to solve the environmental problems affecting the ecology of pollen are needed.

The prevalence of allergic rhinitis in children and adolescents is constantly increasing. However, few studies exist on the relationship between smoking and allergic rhinitis. In addition to conventional cigarettes, electronic and heated cigarettes have recently been introduced, which have several harmful effects. It is hypothesized that smoking and rhinitis are correlated; however, this relationship is complex. Previous studies reported that exposure to smoking during pregnancy is associated with allergic rhinitis development.Unlike the varied results reported in adults, studies on children and adolescents have often correlated direct/indirect smoke with allergic rhinitis, with prolonged exposure being associated with a higher risk of allergic rhinitis, particularly when exposed at an early age. Nonallergic inflammatory reactions and immunoglobulin E-mediated allergic sensitization are assumed to be the underlying mechanisms for the association between allergic rhinitis and smoking. Measures to reduce smoking are warranted to lower the incidence of allergic rhinitis in children and adolescents and to improve their health.

The global worsening of air pollution has decreased the quality of life. Air pollutants can induce oxidative stress, epigenetic changes, and alterations to microRNA expression in the airway and skin, leading to immune dysregulation. Previous epidemiological studies suggest a strong association between outdoor environmental pollution and childhood allergic disease, especially allergic rhinitis (AR). Moreover, traffic-related air pollution has increased the severity and incidence of AR, and heavy traffic has been associated with an increased prevalence of AR. Thus, this review aimed to define outdoor environmental pollution and clarify the mechanisms by which air pollutants aggravate AR. In addition, we performed a systematic review and meta-analysis to summarize the findings of several domestic and international epidemiological and clinical studies about the effects of air pollution on AR in children.

Among allergic diseases of the Korean pediatric population, allergic rhinitis shows the most rapidly increasing prevalence. Its economic burden is substantial in many Asian countries including South Korea. This investigation of its risk factors aims to reduce the socioeconomic burden by blocking exposure of susceptible individuals to identified causes. However, the risk factors of allergic rhinitis varied considerably depending on the seasons, geographical locations, and populations involved. This review article primarily deals with studies on the risk factors for allergic rhinitis in Korean children that were published during the last 10 years and additionally investigates associated large scale international studies. Our investigation identified several single-nucleotide polymorphisms, inhalant allergens, pollution, tobacco smoke, chemicals, and family affluence as risk factors for allergic rhinitis. In contrast, breastfeeding, older sibling, and microbial diversity were protective factors against allergic rhinitis. This suggests that various genetic and environmental factors might affect the manifestation and presentation of allergic rhinitis complexly. These findings are beneficial as they can provide insights into modifiable risk factors that may hinder the development of allergic rhinitis.

Allergic rhinitis (AR) is one of the most common allergic diseases characterized by stuffy nose, rhinorrhea, sneezing, and itching. Researchers have indicated an increase in the prevalence of AR and younger-age onset during the last few decades. The increasing burden of AR has caused many researchers to investigate time trends of the prevalence of AR and to identify its risk factors. The most commonly used epidemiological studies are cross-sectional ones such as the International Study of Asthma and Allergies in Childhood study and big data from National Health Insurance Service or National Health and Nutrition Examination Survey. However, these studies have many limitations including recall bias, selection bias, and deficit of objective evaluation. Furthermore, crosssectional studies cannot reflect new risk factors associated with the development of AR. New epidemiological studies will be needed to cover genetic factors, environmental changes, microbiomes, and lifestyles that are known to be risk factors for AR. Further studies will be needed to determine the prevalence, natural history, and risk factors of AR in order to advance our understanding of the pathophysiology, prevention, and management of comorbidities of AR.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality in East Asia. This study aimed to develop, for primary care providers, a prediction score using initial symptoms and basic laboratory blood tests to differentiate between SFTS and other endemic zoonoses in Korea.METHODS: Patients aged ≥ 18 years diagnosed with endemic zoonoses during a 3-year period (between January 2015 and December 2017) were retrospectively enrolled from 4 tertiary university hospitals. A prediction score was built based on multivariate logistic regression analyses.RESULTS: Of 84 patients, 35 with SFTS and 49 with other endemic zoonoses were enrolled. In multivariate logistic regression analysis, independent predictors of SFTS included neurologic symptoms (odds ratio [OR], 12.915; 95% confidence interval [CI], 2.173–76.747), diarrhea (OR, 10.306; 95% CI, 1.588–66.895), leukopenia (< 4,000/mm3) (OR, 19.400; 95% CI, 3.290–114.408), and normal C-reactive protein (< 0.5 mg/dL) (OR, 24.739; 95% CI, 1.812–337.742). We set up a prediction score by assigning one point to each of these four predictors. A score of ≥ 2 had 82.9% sensitivity (95% CI, 71.7%–87.5%) and 95.9% specificity (95% CI, 88.0%–99.2%). The area under the curve of the clinical prediction score was 0.950 (95% CI, 0.903–0.997).CONCLUSION: This study finding suggests a simple and useful scoring system to predict SFTS in patients with endemic zoonoses. We expect this strategic approach to facilitate early differentiation of SFTS from other endemic zoonoses, especially by primary care providers, and to improve the clinical outcomes.

Background: Several oncoplastic approaches have been implemented in recent years to enhance cosmetic results and to reduce complications. The round block technique is a volume displacement technique for breast reconstruction after breast-conserving surgery (BCS). However, its indications are currently limited according to tumor location, and its cosmetic results and complications have not been clearly established. We hypothesized that the round block technique could produce favorable cosmetic results without major complications regardless of tumor location or nipple-tumor distance, below a certain resected tumor volume and tumor-breast volume ratio. Methods: All breast reconstructions using the round block technique after BCS were included in this analysis. Patients’ data were reviewed retrospectively to investigate complications during follow-up, and clinical photos were used to evaluate cosmetic results. The relationships of tumor location, nipple-tumor distance, tumor volume, and the tumor-breast volume ratio with cosmetic results were investigated. Results: In total, 108 breasts were reconstructed. The mean resected tumor volume was 30.2±15.0 mL. The cosmetic score was 4.5±0.6 out of 5. Tumor location, nipple-tumor distance, tumor volume, tumor-breast volume ratio, radiotherapy, and chemotherapy had no significant effects on cosmetic results or complications. There were no major complications requiring reoperation. Conclusions Breast reconstruction using the round block technique after BCS can lead to good cosmetic results without major complications regardless of the tumor location, nipple-tumor distance, radiotherapy, or chemotherapy. Below the maximum tumor volume (79.2 mL) and the maximum tumor-breast volume ratio (14%), favorable results were consistently obtained.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality in East Asia. This study aimed to develop, for primary care providers, a prediction score using initial symptoms and basic laboratory blood tests to differentiate between SFTS and other endemic zoonoses in Korea. METHODS: Patients aged ≥ 18 years diagnosed with endemic zoonoses during a 3-year period (between January 2015 and December 2017) were retrospectively enrolled from 4 tertiary university hospitals. A prediction score was built based on multivariate logistic regression analyses. RESULTS: Of 84 patients, 35 with SFTS and 49 with other endemic zoonoses were enrolled. In multivariate logistic regression analysis, independent predictors of SFTS included neurologic symptoms (odds ratio [OR], 12.915; 95% confidence interval [CI], 2.173–76.747), diarrhea (OR, 10.306; 95% CI, 1.588–66.895), leukopenia (< 4,000/mm3) (OR, 19.400; 95% CI, 3.290–114.408), and normal C-reactive protein (< 0.5 mg/dL) (OR, 24.739; 95% CI, 1.812–337.742). We set up a prediction score by assigning one point to each of these four predictors. A score of ≥ 2 had 82.9% sensitivity (95% CI, 71.7%–87.5%) and 95.9% specificity (95% CI, 88.0%–99.2%). The area under the curve of the clinical prediction score was 0.950 (95% CI, 0.903–0.997). CONCLUSION This study finding suggests a simple and useful scoring system to predict SFTS in patients with endemic zoonoses. We expect this strategic approach to facilitate early differentiation of SFTS from other endemic zoonoses, especially by primary care providers, and to improve the clinical outcomes.