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.

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.

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.

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.

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.

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.

PURPOSE: Rhinitis is a nasal inflammatory disease in children and adolescents. However, little is known about the phenotypes and characteristics of allergic rhinitis (AR) in Korean children and adolescents. The objective of this study was to analyze the symptoms and comorbidities of rhinitis, to compare AR to non-allergic rhinitis (NAR), and to reveal the phenotypes and features of AR in a Korean pediatric population. METHODS: Patients under 18 years of age with rhinitis symptoms were recruited from January 2013 to January 2015 by pediatric allergists. We analyzed symptoms, phenotypes, comorbidities, and allergen sensitization in this cross-sectional, multicenter study. RESULTS: Medical records were collected from 11 hospitals. The AR group has 641 (68.3%) patients, with 63.2% of boys and 7.5 (±3.4) years of mean age. The NAR group has 136 (14.5%) patients, with 55.1% of boys and 5.5 (±2.9) years of mean age. Moderate-severe persistent AR affected 41.2% of AR patients. Nasal obstruction was more common in NAR patients (P<0.050), whereas AR patients sneezed more (P<0.050) and more commonly had conjunctivitis, asthma, and otitis media (P<0.050). Sinusitis was the most common comorbidity in both groups. Allergen sensitization was caused by house dust mites (HDMs) (90.2%), pollen (38.7%), and animal dander (24.8%) in AR patients. Pollen and animal dander sensitization significantly increased age-dependently (P<0.050), but 91.9% of AR patients were already sensitized to HDMs before 5 years old. CONCLUSIONS: Our study revealed that AR was more prevalent than NAR and that 41.2% of AR presented with moderate-severe disease in Korean pediatric populations. Sinusitis was the most common comorbidity, and sleep disturbance was associated with the severity of rhinitis. The majority of AR patients were sensitized to HDMs in preschool ages. Further studies, including nationwide and longitudinal data, will help understand the relationship between these diseases.
Adolescent* ; Animals ; Asthma ; Child* ; Comorbidity* ; Conjunctivitis ; Dander ; Humans ; Medical Records ; Nasal Obstruction ; Otitis Media ; Phenotype* ; Pollen ; Pyroglyphidae ; Rhinitis* ; Rhinitis, Allergic ; Sinusitis

OBJECTIVES: Bedding in childcare centers (CCCs) can hold house dust mite (HDM) allergens. This study examined whether HDM allergen levels can be reduced through the distribution of an educational newsletter on bedding control to parents of CCC children in Korea. METHODS: All 38 CCCs were measured for Der 1 (sum of Der f 1 and Der p 1) concentrations on classroom floors and bedding before the intervention. Educational newsletters on children’s bedding control were sent to 21 CCCs by mail, and teachers were asked to distribute the newsletters to the parents of the children (intervention group). The remaining 17 CCCs were not sent newsletters (control group). The measurement of Der 1 concentrations in 38 CCCs was repeated after the intervention. Dust samples were collected with a vacuum cleaner and analyzed using enzyme-linked immunosorbent assay methods. RESULTS: The Der 1 concentrations on the bedding were significantly higher than those on the floors in 38 CCCs at baseline (p<0.05). Although changes of the Der 1 concentrations for the control group (n=17) were not significant, Der 1 concentrations for the intervention group (n=21) decreased significantly from 2077.9 ng/g dust to 963.5 ng/g dust on the floors and from 3683.9 ng/g dust to 610.4 ng/g dust on bedding (p<0.05). CONCLUSIONS: The distribution of educational newsletters on bedding control to parents may be an effective means of controlling HDMs in CCCs.
Allergens ; Child ; Dust* ; Enzyme-Linked Immunosorbent Assay ; Humans ; Korea* ; Parents ; Periodicals as Topic* ; Postal Service ; Pyroglyphidae* ; Vacuum

OBJECTIVES: Bedding in childcare centers (CCCs) can hold house dust mite (HDM) allergens. This study examined whether HDM allergen levels can be reduced through the distribution of an educational newsletter on bedding control to parents of CCC children in Korea. METHODS: All 38 CCCs were measured for Der 1 (sum of Der f 1 and Der p 1) concentrations on classroom floors and bedding before the intervention. Educational newsletters on children’s bedding control were sent to 21 CCCs by mail, and teachers were asked to distribute the newsletters to the parents of the children (intervention group). The remaining 17 CCCs were not sent newsletters (control group). The measurement of Der 1 concentrations in 38 CCCs was repeated after the intervention. Dust samples were collected with a vacuum cleaner and analyzed using enzyme-linked immunosorbent assay methods. RESULTS: The Der 1 concentrations on the bedding were significantly higher than those on the floors in 38 CCCs at baseline (p<0.05). Although changes of the Der 1 concentrations for the control group (n=17) were not significant, Der 1 concentrations for the intervention group (n=21) decreased significantly from 2077.9 ng/g dust to 963.5 ng/g dust on the floors and from 3683.9 ng/g dust to 610.4 ng/g dust on bedding (p<0.05). CONCLUSIONS: The distribution of educational newsletters on bedding control to parents may be an effective means of controlling HDMs in CCCs.
Allergens ; Child ; Dust* ; Enzyme-Linked Immunosorbent Assay ; Humans ; Korea* ; Parents ; Periodicals as Topic* ; Postal Service ; Pyroglyphidae* ; Vacuum

Huntington's chorea is a rare hereditary disorder of the nervous system. It is inherited as an autosomal dominant disorder and is characterized by progressive chorea, dementia and psychiatric disturbances. The best anesthetic technique is yet to be established for these patients with increased risk of aspiration due to involvement of pharyngeal muscles and an exaggerated response to sodium thiopental and succinylcholine. The primary goal in general anesthesia for these patients is to provide airway protection and a rapid and safe recovery. We report the anesthetic management of a 51-year-old patient with Huntington's chorea admitted for an emergency operation.
Anesthesia, General ; Bronchoscopes ; Chorea ; Dementia ; Emergencies ; Humans ; Huntington Disease ; Intubation ; Nervous System ; Pharyngeal Muscles ; Sodium ; Succinylcholine ; Thiopental