Associations between pollen and allergic rhinitis in children and adolescents

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.

Effects of outdoor air pollution on children with 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.

Association of Maternal Hypertensive Disorders During Pregnancy With Severe Bronchopulmonary Dysplasia: A Systematic Review and Meta-Analysis

Background@#This meta-analysis was performed to examine the association between maternal hypertension during pregnancy (HDP) and neonatal bronchopulmonary dysplasia (BPD). @*Methods@#We systematically searched PubMed, EMBASE, the Cochrane Library, and the KoreaMed database for relevant studies. We used the Newcastle-Ottawa Scale for quality assessment of all included studies. The meta-analysis was performed using Comprehensive Meta-Analysis software (version 3.3). @*Results@#We included 35 studies that fulfilled the inclusion criteria; the total number of infants evaluated came to 97,399 through review process. Maternal HDP was not significantly associated with any definition of BPD, i.e., oxygen dependency at 36 weeks of gestation (odds ratio [OR], 1.162; 95% confidence interval [CI], 0.991–1.362; P = 0.064) in pooled analysis of 29 studies or oxygen dependency at 28 days of age (OR, 1.084; 95% CI, 0.660–1.780; P = 0.751) in pooled analysis of 8 studies. Maternal HDP was significantly associated only with severe BPD (OR, 2.341; 95% CI, 1.726–3.174; P < 0.001). BPD was not associated with HDP in the overall analysis (OR, 1.131; 95% CI, 0.977–1.309; P = 0.100) or subgroup analysis according to the definition of HDP. @*Conclusion@#Maternal HDP was not associated with neonatal BPD defined by the duration of oxygen dependency (at either 36 weeks of gestation or 28 days of life) but was associated with severe BPD.

Risk factors and protective factors in pediatric patients with allergic rhinitis

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.

Main epidemiological characteristics and natural history of pediatric 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.

The current status and issue of food allergen labeling in Korea

With increasing need to prevent serious food allergy reactions, Korean food allergen labeling regulation has been revised repeatedly. This paper aims to summarize current statuses of food allergen labeling in Korea and foreign countries and to analyze the issue of food allergen labeling regulation. Korean food labeling regulation currently requires 19 items and 22 foods to be reported on labels (eggs, milk, buckwheat, peanut, soybean, wheat, mackerel, crab, shrimp, pork, peach, tomato, sulfite, walnut, chicken, beef, squid, shellfish, and pine nut). However, some common food triggers (for example, almond, cashew nut, and kiwi fruit) are not included in the current labeling regulation. Another issue is that the Korean labeling regulation has not yet been fully implemented for nonprepacked foods; thus, consumers still have difficulty in correctly identifying allergenic ingredients in food. It should be assessed whether warning statements for cross-contamination are reasonable. To prevent the occurrence of serious reactions from accidental ingestion, efforts must be made to solve recently raised issues including the items required to be listed on food labels, the system of standards for labeling and display methods.

Infantile Anaphylaxis in Korea: a Multicenter Retrospective Case Study

BACKGROUND: Anaphylaxis is increasing in young children. The aim of the present study was to analyze the clinical characteristics of anaphylaxis in Korean infants, with a focus on food triggers. METHODS: The study analyzed the medical records of infants aged 0 to 2 years old who had been diagnosed with anaphylaxis in 23 secondary or tertiary hospitals in Korea. RESULTS: We identified 363 cases of infantile anaphylaxis (66.9% male). Cutaneous symptoms were most prevalent (98.6%), followed by respiratory (83.2%), gastrointestinal (29.8%), and neurologic (11.6%) symptoms. Cardiovascular symptoms were noted in 7.7% of the cases. Most of the cases of anaphylaxis (338; 93.1%) were induced by foods. The most common trigger food was cow's milk and cow's milk products (43.8%), followed by hen's eggs (21.9%), walnuts (8.3%), wheat (7.7%), peanuts (4.8%), other nuts (3.0%), and fish (2.1%). In cow's milk-induced anaphylaxis cases, more than half the cases had cow's milk specific immunoglobulin E (sIgE) levels that were lower than the diagnostic decision points (DDPs), which is 5 kUA/L for those under the age of 1 and 15 kUA/L for those over the age of 1. In anaphylaxis induced by hen's egg, most of the cases (91.8%) had hen's egg sIgE levels that were higher than the DDP, which is 2 kUA/L for those under the age of 2 and 7 kUA/L for those over the age of 2. Of the infantile anaphylaxis cases, 46.8% had been treated with epinephrine, and 25.1% had been prescribed an epinephrine auto-injector. CONCLUSION: Cow's milk is the most frequent trigger food of anaphylaxis in Korean infants. However, we found no significant correlation between the sIgE level and clinical severity. Education is required regarding the importance of epinephrine as the first line therapy for anaphylaxis and on properly prescribing epinephrine for infants with a history of anaphylaxis.

Epidemiology of food allergy in Korean children

Food allergy has emerged as an important public health problem affecting people of all ages in many countries. The prevalence varies according to age, geographic regions, and ethnicity. For several years, many studies have suggested that the prevalence of food allergy is increasing at an alarming rate, for unclear reasons. Conversely, some studies have also provided findings that sensitization to common food allergens did not increase. Increased recognition rather than an actual increase in patients with IgE-mediated food allergy might lead to the increases in the prevalence of self-reported or physician-diagnosed food allergy. It is also noted that the prevalence of food allergy differs even in the same region according to the study design, i.e., hospital-based or community-based studies. Despite these limitations, epidemiologic data are important because they provide useful information on diagnosis, treatment, and prevention of food allergy. This review focuses on advances in the epidemiology of food allergy in Korean children.

Age-Based Causes and Clinical Characteristics of Immediate-Type Food Allergy in Korean Children

PURPOSE: Age-based causes and clinical characteristics of immediate-type food allergy (FA) have not been sufficiently studied. Therefore, we investigated age-dependent clinical profiles of FA in Korean children through an extensive multicenter investigation. METHODS: Using a case report form developed by the authors, a retrospective medical record review was performed of patients (0-18 years old) diagnosed with immediate-type FA between September 2014 and August 2015 in 14 tertiary hospitals in Korea. RESULTS: A total of 1,353 children and adolescents, 93% younger than 7 years, were enrolled in the present study, and 1,661 cases of immediate-type FA were recorded in these patients. The 7 major causative foods were cow's milk (28.1%), hen's eggs (27.6%), wheat (7.9%), walnuts (7.3%), peanuts (5.3%), buckwheat (1.9%), and shrimps (1.9%). Categorizing the patients into 4 age groups revealed that the most common causative food was different for each age group: cow's milk (<2 years), walnuts (2–6 years), walnuts (7–12 years), and buckwheat (13-18 years). The onset time of symptoms was less than 10 minutes in 49%, between 10 and 30 minutes in 17%, and between 30 minutes and 2 hours in 34% of cases. Food-induced anaphylaxis was reported in 506 (30.5%) out of 1,661 cases, and the 7 major causes of food-induced anaphylaxis was cow's milk (27.5%), hen's eggs (21.9%), wheat (11.3%), walnuts (10.5%), peanuts (5.9%), buckwheat (4.2%), and pine nuts (3.0%). The proportion of anaphylaxis was highest in the patients allergic to buckwheat (67.7%), followed by those allergic to pine nuts (57.7%), walnuts (43.8%), wheat (43.5%), and peanuts (34.1%). CONCLUSIONS: The 5 major causative foods of immediate-type FA in Korean children were cow's milk, hen's eggs, wheat, walnuts, and peanuts. The distribution of causative foods was considerably distinctive according to different age groups. Anaphylaxis was reported in 30.5% of immediate-type FA cases.

Assessment of leukotriene E4 in exhaled breath condensate as a marker of inflammation and therapeutic effect in allergic rhinitis children

PURPOSE: Recent studies have shown that the cysteinyl leukotriene (cysLT) of exhaled breath condensate (EBC) could be predictive of inflammatory status and effectiveness of treatment in allergic disease. The aim of this study was to evaluate the inflammation and therapeutic effectiveness of cysLT in EBC in pediatric patients with allergic rhinitis (AR). METHODS: We enrolled 34 healthy children (median age, 4 years 10 months) and 67 AR children (median age, 5 years 1 month). All of the AR patients received intranasal steroid (fluticasone furoate) once daily for 2 weeks. After 2 week of fluticasone furoate treatment, they were classified into 2 groups: the fluticasone furoate (F) and montelukast (M) groups. We treated each group for another 8 weeks. To evaluate the therapeutic effectiveness, we used symptom score (SS) and EBC leukotriene E4 (LTE4). EBC samples were collected with RTube. Each parameter was checked at 0, 2, and 10 weeks of therapy. RESULTS: Most of the AR patients showed clinical improvement with 2- and 10-week fluticasone therapy (F group: 0-week SS, 5.6; 2-week SS, 3.6; 10-week SS, 2.1; P<0.01; M group: 0-week SS, 4.8; 2-week SS, 3.2; 10-week SS, 1.9: P<0.01). LTE4 levels were higher in AR patients than in control subjects (0 week: 87 pg/mL vs. 18 pg/mL) and were reduced after 2 weeks of fluticasone treatment (F group: 90→51.6 pg/mL, P<0.01; M group: 84→46.1 pg/mL, P<0.01). After 10 weeks of treatment, there was no significant difference in the LTE4 level between the F and M groups. CONCLUSION: LTE4 in EBC may be useful for evaluating inflammation and therapeutic effectiveness in patients with allergic rhinitis.

Comorbidities and Phenotypes of Rhinitis in Korean Children and Adolescents: A Cross-sectional, Multicenter Study

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.

Reference Values and Utility of Serum Total Immunoglobulin E for Predicting Atopy and Allergic Diseases in Korean Schoolchildren

The present study aimed to investigate the distribution of total serum immunoglobulin E (IgE) levels in Korean schoolchildren and to evaluate its utility in the prediction of atopy and allergic diseases. A nationwide, cross-sectional survey was conducted in first grade students from randomly selected elementary and middle schools. Total IgE levels were measured by ImmunoCAP. Skin prick tests were performed for 18 common inhalant allergens to determine the presence of atopy. Children aged 12–13 years and parents of children aged 6–7 years were asked to complete questionnaire assessing allergic diseases. The cut-off levels of total IgE were determined by analyzing receiver operating characteristic curves. The median total IgE level was 86.7 kU/L (range: 1.5–4,523.1) in 3,753 children aged 6–7 years and 94.7 kU/L (range: 1.5–3,000.0) in 3,930 children aged 12–13 years. Total IgE concentrations were higher in children with atopy or allergic diseases than in those without (all P < 0.001). At the cut-off value of 127.7 kU/L, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were 67.1%, 75.4%, 65.4%, and 76.7%, respectively, in elementary schoolchildren. At the cut-off value of 63.0 kU/L, sensitivity, specificity, PPV, and NPV were 81.9%, 66.6%, 75.0%, and 75.1%, respectively, in middle schoolchildren. PPV and NPV were ≥ 70% when cut-offs of 258.8 kU/L and 38.4 kU/L were used for the diagnosis of atopy in 6–7 year-olds and 12–13 year-olds, respectively. This nationwide population-based study provided the first normal reference ranges of total IgE in Korean schoolchildren.

Chronic cough in children

Cough is one of the common symptoms, which is usually related to respiratory infections for children. This symptom is not considered crucial. Published data reported that the community prevalence of chronic cough in primary school children is 5%-10%, while the prevalence is likely to be higher in younger children. The cause of persistent cough should be investigated. There were significant differences in the causes and management for cough according to age. Chronic cough is defined as duration of 4 weeks or longer. Common culprits for chronic cough in children are different from those in adults. The authors reviewed articles about chronic cough of children to help improve the understanding and management for pediatric chronic cough.

A Multicenter Retrospective Case Study of Anaphylaxis Triggers by Age in Korean Children

PURPOSE: Although anaphylaxis is recognized as an important, life-threatening condition, data are limited regarding its triggers in different age groups. We aimed to identify anaphylaxis triggers by age in Korean children. METHODS: We performed a retrospective review of medical records for children diagnosed with anaphylaxis between 2009 and 2013 in 23 secondary or tertiary hospitals in South Korea. RESULTS: A total of 991 cases (mean age=5.89±5.24) were reported, with 63.9% involving patients younger than 6 years of age and 66% involving male children. Food was the most common anaphylaxis trigger (74.7%), followed by drugs and radiocontrast media (10.7%), idiopathic factors (9.2%), and exercise (3.6%). The most common food allergen was milk (28.4%), followed by egg white (13.6%), walnut (8.0%), wheat (7.2%), buckwheat (6.5%), and peanut (6.2%). Milk and seafood were the most common anaphylaxis triggers in young and older children, respectively. Drug-triggered anaphylaxis was observed more frequently with increasing age, with antibiotics (34.9%) and nonsteroidal anti-inflammatory drugs (17.9%) being the most common causes. CONCLUSIONS: The most common anaphylaxis trigger in Korean children was food. Data on these triggers show that their relative frequency may vary by age.

Analysis of regional prevalence of allergic diseases in Korean school children

PURPOSE: This study aimed to analyze the prevalence of allergic diseases in Korean schoolchildren according to their residential areas in 2010. METHODS: A nationwide, cross-sectional study was conducted in children aged 6-7 years (n=4,003) and adolescents aged 12-13 years (n=4,112) who were randomly selected. Demographic and disease-related information was obtained through a Korean version of ISAAC (International Study of Asthma and Allergies in Childhood) questionnaire, and skin prick tests for 18 inhalant allergens were performed. RESULTS: There was statistically significant regional difference in the prevalence of allergic rhinitis (AR) (P<0.05). The regions with highest and lowest prevalence in 12- to 13-year-old children were as follows: Chungcheong and Honam in "Diagnosis of AR, ever" (33.7% vs. 24.5%), Jeju and Yeongnam in "Treatment of AR, last 12 months" (25.5% vs. 18.0%), Chungcheong and Yeongnam in "Rhinitis with sensitization" (31.6% vs. 23.6%). The regions with highest and lowest prevalence in 6-7 years old children were as follows: Yeongnam and Seoul in "Diagnosis of AR, ever" (42.1% vs. 31.0%), Yeongnam and Jeju in "Treatment of AR, last 12 months" (31.8% vs. 21.9%), Jeju and Seoul in "Rhinitis with sensitization" (26.0% vs. 18.4%). We also found a regional difference in inhalant allergens among the children with "rhinitis with sensitization" CONCLUSION: The prevalence of AR in children differs according to residential areas in a nationwide survey in 2010 while there is no significant regional difference in the prevalence of asthma and AD.

The Association between Asthma and Invasive Pneumococcal Disease: A Nationwide Study in Korea

The purpose of this study was to investigate the association between asthma and invasive pneumococcal disease (IPD) in Korea. A retrospective population-based cohort study was conducted using the Korean Health Insurance Review and Assessment database 2010-2011. The subjects included 935,106 (2010) and 952,295 (2011), of whom 398 (2010) and 428 (2011) patients with IPD were identified. There was significant difference in the prevalence of IPD in patients with and without asthma (0.07% vs. 0.02% in 2010 and 0.08% vs. 0.01% in 2011; P<0.001). After adjusting for age and gender, patients with asthma showed over a three-fold increased risk of IPD compared with patients without asthma (adjusted odds ratio [aOR] 3.90, 95% confidence interval [CI] 3.02-5.03 in 2010 / aOR, 5.44; 95% CI, 4.10-7.22 in 2011; P<0.001). These findings were also significant in children (aOR, 2.08; 95% CI, 1.25-3.45 in 2010; P=0.005 / aOR, 3.26; 95% CI, 1.74-6.11 in 2011; P<0.001). Although diabetes mellitus was also significantly associated with IPD, relatively low ORs compared with those of asthma were noted (aOR, 1.85; 95% CI, 1.35-2.54 in 2010 / aOR, 2.40; 95% CI, 1.78-3.24 in 2011; P<0.001). Both children and adults with asthma are at increased risk of developing IPD.

An overview and considerations in prescribing H1-antihistamine

H1-antihistamines have been prescribed widely for the treatment of allergic diseases, such as rhinitis, atopic dermatitis, and urticaria besides common colds since the 1940s. H1-antihistamines are classified by chemical structures (akylamine, piperazine, piperidine, ethanolamine, ethylendiamine, and phenothiazine) or functionally by permeability through blood brain barrier (first or second generation). The first generation antihistamines have been prescribed up to now with several adverse effects such as central nervous system dysfunction, anticholinergic and antiserotonic action and cardiotoxicity with overdose. Hence second generation antihistamines are recommended for the treatment of allergic rhinitis and urticaria. Physicians should consider concomitant diseases or medications when prescribing first generation antihistamines.

Erratum: Multicenter Survey on the Economic Burden of Pediatric Allergic Rhinitis / 소아알레르기및호흡기학회지

The funding acknowledgment in this article was omitted as published.

Predisposing Factors Associated With Chronic and Recurrent Rhinosinusitis in Childhood

PURPOSE: There is currently no information regarding predisposing factors for chronic and recurrent rhinosinusitis (RS), although these are considered to be multifactorial in origin, and allergic diseases contribute to their pathogenesis. We evaluated the predisposing factors that may be associated with chronic and recurrent RS. METHODS: In this prospective study, we examined patients with RS younger than 13 years of age, diagnosed with RS at six tertiary referral hospitals in Korea between October and December, 2006. Demographic and clinical data related to RS were recorded and analyzed. RESULTS: In total, 296 patients were recruited. Acute RS was the most frequent type: 56.4% of the patients had acute RS. The prevalences of other types of RS, in descending order, were chronic RS (18.9%), subacute RS (13.2%), and recurrent RS (11.5%). Factors associated with recurrent RS were similar to those of chronic RS. Patients with chronic and recurrent RS were significantly older than those with acute and subacute RS. The prevalences of allergic rhinitis, atopy, and asthma were significantly higher in patients with chronic and recurrent RS than those with acute and subacute RS. CONCLUSIONS: An association between atopy and chronic/recurrent RS, compared to acute and subacute RS, suggests a possible causal link.

Multicenter Survey on the Economic Burden of Pediatric Allergic Rhinitis / 소아알레르기및호흡기학회지

PURPOSE: The prevalence of allergic rhinitis is rapidly increasing and results in relatively high socio-economic burden on their family and community. However, studies on the economic burden of pediatric allergic rhinitis in Korea are limited. Therefore, we conducted this study to investigate the impact of pediatric allergic rhinitis on economic burden. METHODS: Two hundred sixty two children with allergic rhinitis were enrolled in 6 secondary or tertiary medical centers in Seoul from July to September, 2008. We collected data of the economic burden of allergic rhinitis (direct medical costs, direct nonmedical costs, and indirect costs) by face to face questionnaire survey. We compared the economic burden according to the severity and the duration of allergic rhinitis. RESULTS: The mean age of subjects was 6.54 years, and male were 174 (66.4%). Direct medical costs (10,000 Korean Won/yr) were 177.75, and direct nonmedical costs were 57.92. Although, there was no statistical significance, direct medical costs showed increasing trends in severe allergic rhinitis.(P=0.053) In addition, direct medical costs were positively correlated with duration of allergic rhinitis.(R=0.195, P=0.002). About 17% of the parents who care the allergic rhinitis children experienced the work absence due to their child's illness. CONCLUSION: The economic burdens of allergic rhinitis were positively correlated with the severity and duration of illness. Particularly costs for alternative medicine including oriental medicine were related with severity and duration allergic rhinitis. Therefore, special efforts for education with evidence based treatment strategy are necessary to decrease the economic burden of allergic rhinitis.