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 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.

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.

A 15-year-old Schnauzer, showing right exophthalmos, was diagnosed as adenocarcinoma originated from the third eyelid gland. On computed tomography, a normal right third eyelid gland was not observed. Instead, a heterogeneous cystic mass invaded the retrobulbar space and displaced the eye globe dorsolaterally. In addition, lysis of the bony nasolacrimal duct was found, which was considered the tumor invasion. These findings indicated that third eyelid gland adenocarcinoma should be considered when a retrobulbar mass is found ventromedial to the globe without observation of the normal third eyelid and accompanies osteolysis of the bony nasolacrimal duct in dogs showing exophthalmos.

PURPOSE: Adherence is a major component of successful medical treatment. However, non-adherence remains a barrier to effective delivery of healthcare worldwide. METHODS: Twenty healthcare facilities (secondary or tertiary hospitals) belonging to the Korean Academy of Pediatric Allergy and Respiratory Diseases (KAPARD) participated. Questionnaires were given to patients currently receiving treatment in the form of inhalant useor oral intake or transdermal patch for mild to moderate asthma. RESULTS: A total of 1,838 patients responded to the questionnaire. Mean age was 5.98 ± 3.79 years (range: 0-18 years). With help from their caregivers, the percentage of patients that answered “taking as prescribed” was 38.04% for inhalant users, 50.09% for oral medication users and 67.42% for transdermal users. Transdermal patch users had significantly greater adherence compared to the other 2 groups (P < 0.001). The 34.15% of inhalant users, 70.33% of oral medication users and 93.00% of transdermal patch users felt that their medication delivery system was “Easy” or “Very easy” to use (P < 0.001). “Method of administration” was deemed to be the most difficult part of the treatment regimen to follow, and 76.7% of patients preferred once-daily administration (i.e., “Frequency of administration”). CONCLUSIONS: Asthma medication adherence in young children was found to be better in the transdermal patch group. This may be due to requiring fewer doses and easy to follow instructions. From an adherence point of view, the transdermal patch seems more useful for long-term asthma control in children compared to oral or inhaled medicine.
Asthma ; Caregivers ; Child ; Delivery of Health Care ; Humans ; Hypersensitivity ; Korea ; Medication Adherence ; Transdermal Patch

Chronic cough is common in the community and causes significant morbidity. Several factors may underlie this problem, but comorbid conditions located at sensory nerve endings that regulate the cough reflex, including rhinitis, rhinosinusitis, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease, are considered important. However, chronic cough is frequently non-specific and accompanied by not easily identifiable causes during the initial evaluation. Therefore, there are unmet needs for developing empirical treatment and practical diagnostic approaches that can be applied in primary clinics. Meanwhile, in referral clinics, a considerable proportion of adult patients with chronic cough are unexplained or refractory to conventional treatment. The present clinical practice guidelines aim to address major clinical questions regarding empirical treatment, practical diagnostic tools for non-specific chronic cough, and available therapeutic options for chronic wet cough in children and unexplained chronic cough in adults in Korea.
Adult* ; Asthma ; Bronchitis ; Child* ; Cough* ; Eosinophils ; Evidence-Based Medicine ; Gastroesophageal Reflux ; Humans ; Korea* ; Referral and Consultation ; Reflex ; Rhinitis ; Sensory Receptor Cells

BACKGROUND: To evaluate the therapeutic benefits of the treat-to-target (T2T) strategy for Asian patients with early rheumatoid arthritis (RA) in Korea. METHODS: In a 1-year, multicenter, open-label strategy trial, 346 patients with early RA were recruited from 20 institutions across Korea and stratified into 2 groups, depending on whether they were recruited by rheumatologists who have adopted the T2T strategy (T2T group) or by rheumatologists who provided usual care (non-T2T group). Data regarding demographics, rheumatoid factor titer, anti-cyclic citrullinated peptide antibody titer, disease activity score of 28 joints (DAS28), and Korean Health Assessment Questionnaire (KHAQ) score were obtained at baseline and after 1 year of treatment. In the T2T group, the prescription for disease-modifying antirheumatic drugs was tailored to the predefined treatment target in each patient, namely remission (DAS28 < 2.6) or low disease activity (LDA) (2.6 ≤ DAS28 < 3.2). RESULTS: Data were available for 163 T2T patients and 162 non-T2T patients. At the end of the study period, clinical outcomes were better in the T2T group than in the non-T2T group (LDA or remission, 59.5% vs. 35.8%; P < 0.001; remission, 43.6% vs. 19.8%; P < 0.001). Compared with non-T2T, T2T was also associated with higher rate of good European League Against Rheumatism response (63.0% vs. 39.8%; P < 0.001), improved KHAQ scores (−0.38 vs. −0.13; P = 0.008), and higher frequency of follow-up visits (5.0 vs. 2.0 visits/year; P < 0.001). CONCLUSION: In Asian patients with early RA, T2T improves disease activity and physical function. Setting a pre-defined treatment target in terms of DAS28 is recommended.
Antirheumatic Agents ; Arthritis, Rheumatoid* ; Asian Continental Ancestry Group* ; Demography ; Follow-Up Studies ; Humans ; Joints ; Korea* ; Multicenter Studies as Topic* ; Prescriptions ; Rheumatic Diseases ; Rheumatoid Factor ; Treatment Outcome