Associations Between Phthalate, Eosinophil, and Aeroallergen Sensitization in Schoolchildren

Background@#Phthalates and bisphenol A (BPA) are endocrine-disrupting chemicals and may cause immunological disorders in children. Therefore, according to the region, we investigated urinary phthalates and BPA levels and the relationship between urinary phthalate, aeroallergen sensitization, and eosinophil count during the coronavirus disease 2019 pandemic. @*Methods@#In total, 203 schoolchildren (134 residential and 69 industrial) aged 7–10 years were enrolled between July 2021 and July 2022. The BPA, metabolites of four high-molecularweight phthalates (Σ4HMWP) and three low-molecular-weight phthalates (Σ3LMWP), were measured in the urine samples. Total eosinophil count and transepidermal water loss (TEWL) were also measured along with the skin prick test. @*Results@#The two groups had no differences in terms of BPA. The industrial group had significantly more plastic container usage, and there was a difference in the Σ3LMWP (P < 0.001) between the two groups but no difference in the Σ4HMWP (P = 0.234). The quartiles of urinary Σ4HMWP and Σ3LMWP (P < were not associated with the total eosinophil count, vitamin D level, or TEWL. After adjusting for cofactors, the quartiles of urinary Σ4HMWP and Σ3LMWP were significantly associated with total eosinophil count (P < 0.001) but not with aeroallergen sensitization or vitamin D. @*Conclusion@#Exposure to phthalates was significantly associated with eosinophil count but not with aeroallergen sensitization or vitamin D. Therefore, reducing the use of plastic containers may effectively prevent exposure to phthalates and reduce Th2 cell-mediated inflammation in children.

Association Between Receipt of General Anesthesia During Childhood and Attention Deficit Hyperactive Disorder and Neurodevelopment

Background@#There are inconsistent reports regarding the association between general anesthesia and adverse neurodevelopmental and behavioral disorders in children. @*Methods@#This nationwide administrative cohort study included children born in Korea between 2008 and 2009, and followed until December 31, 2017. The cohort included 93,717 participants who received general anesthesia with endotracheal intubation (ETI) who were matched to unexposed subjects in a 1:1 ratio. General anesthesia was defined by National Health Insurance Service treatment codes with intratracheal anesthesia, and the index date was the first event of general anesthesia. The primary outcome was attention deficit hyperactive disorder (ADHD), which was defined as at least a principal diagnosis of 10th revision of the International Classification of Diseases code F90.X after the age of 72 months.Neurodevelopment, which was assessed using a developmental screening test (Korean-Ages and Stages Questionnaire [K-ASQ]), was a secondary outcome. The K-ASQ is performed annually from 1 to 6 years of age and consists of 5 domains. The association between general anesthesia and ADHD was estimated using a Cox hazard model, and its association with neurodevelopment was estimated using a generalized estimation equation, with control for multiple risk factors beyond 1 year after the index date. @*Results@#The median age at the index date was 3.8 (95% confidence interval [CI], 1.7–5.8) years, and there were 57,625 (61.5%) men. During a mean follow-up period of 5 years, the incidence rate of ADHD was 42.6 and 27.7 per 10,000 person-years (PY) in the exposed and unexposed groups, respectively (absolute rate difference 14.9 [95% CI, 12.5–17.3] per 10,000 PY). Compared to the unexposed group, the exposed group had an increased risk of ADHD (adjusted hazard ratio, 1.41 [95% CI, 1.30–1.52]). In addition, a longer duration of anesthesia with ETI and more general anesthesia procedures with ETI were associated with greater risk of ADHD. General anesthesia with ETI was also associated with poorer results in the K-ASQ. @*Conclusion@#Administration of general anesthesia with ETI to children is associated with an increased risk of ADHD and poor results in a neurodevelopmental screening test.

Personal Exposure to Total VOC Is Associated With Symptoms of Atopic Dermatitis in Schoolchildren

Background@#The urinary levels of volatile organic compound (VOC) metabolites provide individual exposure levels compared to data obtained by measuring these compounds in ambient air. We aimed to investigate the association between personal urinary concentrations of VOC metabolites and symptoms of atopic dermatitis in schoolchildren. @*Methods@#Nine urinary VOC metabolites were analyzed from urine samples of 149 children. Diagnosis of atopic dermatitis was determined using standardized questionnaires. Pediatricians visited the schools and rated the severity of symptoms using the SCORing Atopic Dermatitis (SCORAD) in all children. @*Results@#Forty-five children (30.2%) had atopic dermatitis based on the International Study of Asthma and Allergies in Childhood (ISAAC) results and 35 children (23.8%) had symptoms of atopic dermatitis with positive SCORAD index values (defined as SCORAD ≥ 5). Children with benzylmercapturic acid detected in personal urines were associated with presence of atopic dermatitis and positive SCORAD index values. Children in the highest quartile of mandelic acid concentration were associated with presence of atopic dermatitis and positive SCORAD results. @*Conclusion@#Personal exposure to VOCs, as indicated by urinary levels of VOC metabolites, was associated with presence of atopic dermatitis and the SCORAD index value.

Growth in Exclusively Breastfed and Non-exclusively Breastfed Children:Comparisons with WHO Child Growth Standards and Korean National Growth Charts

Background@#This study examined the relationship of infant feeding with anthropometric indices of children during their first six years of life relative to the Korean National Growth Charts (KNGC) and the World Health Organization Child Growth Standards (WHO-CGS). @*Methods@#The study population consisted of 547,669 Korean infants and children who were 6 months-old to 6 years-old (born in 2008–2009) and participated in the National Health Screening Program for Infants and Children. Data on height, weight, and type of feeding during the first 6 months (exclusively breastfed [BF] vs. mixed- or formula-fed [FF]) were analyzed. @*Results@#BF boys and girls were significantly shorter and lighter than FF counterparts from the age of 6 months to 4 years, but these differences were not significant after the age of 4 years. BF boys and girls only had significantly lower body mass index at the age of 2 years. Under the age of 2 years 6 months, and especially under the age of 1 year, BF boys and girls were significantly taller and heavier than the 50th percentile values of the 50th percentile value of the WHO-CGS. @*Conclusion@#In this study using large-scaled national data, Korean breastfed children are shorter and lighter by 3 years 6 months–4 years 6 months, but afterward, there is no significant difference from those who had mixed- or formula-feeding. Substantial disparities in the anthropometric indices of Korean infants under the age of 1 compared to KNCG and WHO-CGS were found, regardless of their infantile feeding types. Our results emphasize the importance of constructing a nationwide reference chart based on actual measurements of BF Korean infants.

Clinical usefulness of serum procalcitonin to distinguish between viral pneumonia and Mycoplasma pneumonia in children: A multicenter, cross-sectional study

PURPOSE: The aim of this study was to compare the clinical usefulness of serum procalcitonin (PCT) levels in Mycoplasma pneumoniae pneumonia (M. pneumonia) and viral pneumonia in children. METHODS: We retrospectively analyzed the medical records of 348 patients admitted between June 2015 and December of 2015. There were 162 patients with M. pneumonia without virus coinfection (group 1) and 186 patients with viral pneumonia (group 2). All subjects had radiographic evidence of pneumonia with available specimens for both M. pneumonia and viral testing, and levels of serum PCT, white blood cell counts (WBC), neutrophil portion, and C-reactive protein (CRP). Fifty-eight children who performed follow-up sampling at the time of no fever for more than 48 hours were subdivided into group 3 (M. pneumonia with follow-up sampling, n=41) and group 4 (viral pneumonia with follow-up sampling, n=17). RESULTS: No difference was noted in the levels of serum PCT (P=0.168), CRP (P=0.296), WBC (P=0.732), and neutrophil proportion (P=0.069) between groups 1 and 2, after adjusting for age. Serial changes in serum PCT levels between the first and second samples were significant in group 3 (P=0.046). Serial changes in serum CRP levels between the first and second samples were significant in group 4 (P=0.008). CONCLUSION: Serum PCT and CRP levels may change differently after infection according to the etiology of pneumonia.

Seasonal patterns and etiologies of croup in children during the period 2010–2015: A multicenter retrospective study

PURPOSE: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of parainfluenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to examine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. METHODS: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medical records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical information were cross-sectionally reviewed and analyzed. RESULTS: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11–31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hospitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). CONCLUSION: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most common cause of childhood croup; however, croup epidemics could be attributed to other viruses.

Association of Sensitization to Different Aeroallergens With Airway Function and Nasal Patency in Urban Children

PURPOSE: Children with sensitization to aeroallergens have decreased lung function and nasal patency. Our purpose was to determine the association of sensitization to different aeroallergens with airway function and nasal patency. METHODS: Four hundred and eighty-six randomly selected 11 year-old children who lived in Seongnam City were examined. Serum specific immunoglobulin E (IgE) levels against 6 common allergens (Dermatophagoidesfarinae, birch, cat, dog, Japanese hop and Alternaria), impulse oscillometry (IOS) results for the evaluation of airway dysfunction, and acoustic rhinometry for the determination of nasal airway patency were obtained. RESULTS: IOS indicated that children sensitized to Alternaria (n = 38, 7.8%) and dog dander (n = 69, 14.2%) had decreased lung function, based on resistance at 10 Hz (Rrs10; aβ = 0.0072; 95% CI, 0.017, 0.127; P = 0.010) and 1 Hz (Rrs1; aβ = 0.038; 95% CI, 0.001, 0.074; P = 0.042). Children sensitized to D. farinae (n = 281, 57.8%) had decreased post-decongestant nasal volume at 0 to 5 cm (aβ = −0.605; 95% CI, −1.005, −0.205; P = 0.003), but normal IOS results at all measured frequencies (P > 0.05). Increased serum eosinophil level was associated with Rrs1 (P = 0.007) and Rrs2 (P = 0.018) and post-decongestant nasal volume at 0 to 5 cm (aβ = −0.885; 95% CI, −1.331, −0.439; P < 0.001). CONCLUSIONS: Sensitivity to specific aeroallergens, serum eosinophil count and total IgE level had different associations with upper and lower airway dysfunction in urban children.

Current Status of Patient Education in the Management of Atopic Dermatitis in Korea

Patient education is important for successful management of atopic dermatitis; however, due to limited time and resources, patient education remains insufficient. This study aimed to investigate the current state of education provided by Korean dermatologists, pediatric allergists, and allergists to patients with atopic dermatitis. A questionnaire survey consisting of items regarding educational programs for patients with atopic dermatitis was conducted via e-mail. In total, 153 participants responded to the questionnaires, and 26.8% indicated that they have had separate educational programs. The workforce involved in the educational program included nurses, residents or fellows, dieticians, pharmacists, and clinical psychologists. Most education protocols addressed the characteristics and natural course of atopic dermatitis and environmental management. Overall, 96.7% of the participants replied that an additional charge is needed for education; moreover, additional assistance from an academic society or association, in the form of medical staff, organized data, and advertisement, is required to develop and provide a well-structured educational program. A standardized education protocol will effectively provide appropriate education for patients with atopic dermatitis. Arrangement of education fees, covered by the National Health Insurance Service, will lead to the establishment of a structured educational program and participation of an additional medical workforce.

Clinical Efficacy of Allergen-Specific Immunotherapy from Patient and Physician Perspectives

PURPOSE: Allergen-specific immunotherapy (AIT) is the only curative treatment for allergic diseases, but a few allergic patients receive AIT. In this multicenter cross-sectional study, we aimed to explore patient and physician perspectives on AIT through a questionnaire survey. MATERIALS AND METHODS: Allergic patients who received subcutaneous immunotherapy for at least 1 year were asked to answer a questionnaire developed by an expert panel of allergen and immunotherapy workgroup in Korea. RESULTS: A total of 267 patients (adults, 60.3%) with allergic rhinitis (91.4%), asthma (42.7%), or atopic dermatitis (20.2%) from referred hospitals completed the survey. Among patients and physicians, respectively, the overall rates of satisfaction with AIT for allergic rhinitis were 86.4% and 83.3% (kappa agreement=0.234, p<0.001), and those for asthma were 85.3% and 72.9% (kappa agreement=0.373, p<0.001). Moreover, pediatric asthmatic patients reported a significantly higher satisfaction rate than adult asthmatic patients after AIT (p=0.040). Symptom severity (p<0.001, respectively) and drug use for allergic rhinitis and asthma decreased after AIT. However, there was no significant difference in satisfaction rates between children and adults in allergic rhinitis (p=0.736). Interestingly, 35.7% and 35% of allergic rhinitis and asthma patients, respectively, reported experiencing improvement in their symptoms within 6 months of starting AIT. CONCLUSION: In this study evaluating the perspectives of patients and physicians on AIT, the majority of patients were satisfied with the efficacy and safety of AIT, but not its cost. AIT should be recommended for AR and allergic patients.

Literature review and future strategies of childhood respiratory diseases in Korea

Thirty years have passed since the Korean Association of Pediatric Allergy and Respiratory Disease was founded. There have been great changes in the pattern of respiratory diseases in Korean children during the last 30 years with economic development in the country. Pneumonia remains the leading cause of childhood morbidity, despite advances in the prevention and management. The incidence and mortality of pneumonia caused by typical bacterial pathogens have been reduced. However, the predominance of Mycoplasma pneumoniae or virus-associated diseases is emerging, which suggests that novel diagnostic and therapeutic strategies are needed. Viral bronchiolitis is one of the most substantial health burdens for infants and young children worldwide. Although respiratory syncytial virus is the most common pathogen, molecular diagnostic techniques have identified many other viruses including human rhinovirus causing bronchiolitis. Bronchiectasis is a chronic respiratory condition characterized by chronic infection, airway inflammation, and progressive lung function decline. Research into the interactions between early life respiratory infections and development of bronchiectasis is imperative to halt the disease in its origin and improve adult outcomes. Acute respiratory distress syndrome (ARDS) is a severe, life-threatening lung disease with diffuse inflammatory lung injury leading to pulmonary edema and hypoxia. Although many modalities to treat ARDS have been studied, supportive therapies and lung protective ventilator support remains the mainstay. This review focuses on the current trends in research on these childhood respiratory diseases through literature review and aims to investigate the impact of Korean study results in this field.

A Delphi approach to the development of standard questionnaire to investigate asthma in Koreans

PURPOSE: Recently, the prevalence and disease burden of asthma have increased. Thus, the need for early diagnosis and appropriate management of asthma is emerging. However, it is difficult to identify the diagnosis, symptoms and the prevalence of asthma due to lack of reliable investigating items. The purpose of this study was to develop a standardized survey format in order to assess the prevalence of asthma in Koreans. METHODS: We investigated surveys and related information that are utilized to assess asthma diagnosis and prevalence by systematic review. After that, Delphi survey was conducted on 44 Korean allergists in order to develop a standardized survey in Korea. The process consisted of 3 serial rounds across 3 age groups. Each subsequent round narrowed investigating items for the decision of standard set about asthma prevalence, current asthma, and asthma aggravation. RESULTS: Lifetime asthma was defined as “ever doctor-diagnosed asthma” in all age groups. Current asthma was defined as “treatment for asthma during the past 12 months” in all age groups, and “doctor-diagnosed asthma during the past 12 months” was added on the ≥5-year-old and adult groups. “Wheezing ever” was defined as “wheezing at any time in the past,” and current wheeze was defined as “wheezing in the last 12 months.” Asthma aggravation was defined as “visits at the emergency department or admission due to asthma attack within the last 12 months” in all age groups. CONCLUSION: We established applicable nationwide definitions of “lifetime asthma,” “current asthma,” and “asthma aggravation” in Koreans by the Delphi survey.

Serum Periostin Is Negatively Correlated With Exposure to Formaldehyde and Volatile Organic Compounds in Children

Epidemiological studies have shown that exposure to tobacco smoke causing irritation and inflammation in the airways tends to reduce serum periostin concentrations in adults. We now investigate prospective cross-sectional study on 135 Korean students aged 7 years in the first grade who were participating in the Seongnam Atopy Project for Children's Happiness 2016 (SAP2016) cohort. To the best of our knowledge, this is the first study to show significant inverse correlations between serum periostin concentration and exposure to xylene and formaldehyde in children. Our findings suggested the need for caution in using the serum periostin level as a marker for allergic diseases, since exposure to volatile organic compounds and formaldehyde may confound the interpretation of these results.

Erratum: Seasonal Cycle and Relationship of Seasonal Rhino- and Influenza Virus Epidemics With Episodes of Asthma Exacerbation in Different Age Groups

This erratum is being published to correct the printing error on page 517 of the article. Corrections for Fig. 1 and main text in page 519 are needed. The authors apologize for any inconvenience that this may have caused.

Clinical features of Mycoplasma pneumonia in comparison with viral pneumoina in children: A multicenter, cross-sectional study

PURPOSE: This study was conducted to compare clinical features between Mycoplasma pneumonia and viral pneumonia. METHODS: We retrospectively analyzed the medical records of 428 patients requiring hospitalization among children younger than 18 years of age in 5 hospitals in Seoul and Gyeonggi-do. There were 131 patients with M. pneumonia and virus coinfection, 167 patients with M. pneumonia without virus coinfection, and 130 patients with viral pneumonia. All subjects had radiographic evidence of pneumonia with specimens available for both M. pneumonia and viral testing. Virus was identified using the polymerase chain reaction assay in a nasopharyngeal or oropharyngeal swab. M. pneumoniae pneumonia was diagnosed serologically. RESULTS: Human rhinovirus was detected in 60.3% (79 of 131) of children with M. pneumonia accompanied by virus coinfection. Respiratory syncytial virus (RSV) was detected in 38.2% (50 of 130) of children with viral pneumonia. The mean age was significantly lower in the viral pneumonia group than in the M. pneumonia group with and without virus coinfection. The sex distribution did not differ significantly among the 3 study groups. The procalcitonin level was higher in viral pneumonia and erythrocyte sedimentation rate level was higher in the M. pneumonia group although no significant difference was found in C-reactive protein level between the M. pneumonia and viral pneumonia groups. CONCLUSION: Clinical features and inflammatory markers between M. pneumonia and viral pneumonia may be useful for the treatment of community-acquired pneumonia.

Clinical characteristics and genetic variation in respiratory syncytial virus isolated from infants hospitalized due to acute bronchiolitis in Korea during winter season 2016–2017

PURPOSE: Circulating patterns of predominant respiratory syncytial virus (RSV) genotypes in the community may be helpful in understanding molecular epidemiology and predicting future outbreaks of the RSV genotype. We investigated the association of genetic variations in RSV with acute severe bronchiolitis in infants. METHODS: We reviewed medical records of infants younger than 1 year of age hospitalized due to acute bronchiolitis between November 2016 and February 2017. Subjects were classified as severe or mild based on the use of mechanical or noninvasive ventilation. The associations between severity of the disease, sex, age at admission, oxygen saturation at admission and laboratory test results were analyzed. RSV sequence analysis was performed in the severe group. RESULTS: Among 114 infants, 80 underwent respiratory viral polymerase chain reaction using nasopharyngeal swab; of these, 53 (66.3%) showed positive for RSV. Of the 53 RSV-positive samples, 9 were categorized as the severe group and 44 were categorized as the mild group. Male sex, young age, longer duration of admission, minimum SaO2 at admission and bronchiolitis severity score were significantly correlated with disease severity in the severe group than in the mild group (all variables, P < 0.001). Phylogenetic and sequence analysis in the severe group revealed 8 RSV-A, ON1 genotype and 1 RSV-B, BA4 genotype. CONCLUSION: Phylogenetic types of RSV in subjects of the severe group were RSV-A, ON1 genotype or RSV-B, BA4 genotype which were prevalent in the Korean community at the same time. Our study showed that disease severity was not significantly associated with RSV genotypic evolution or antigenic drift in Korea during winter season 2016–17.

Proper allergen selection for serum specific IgE test in children

Identifying allergic sensitization is important for the proper diagnosis and management of allergic diseases. Skin prick testing and measuring serum specific IgE antibodies are standard tests to confirm allergic sensitization. Skin prick testing has many advantages, but it is difficult to perform on young children. Serum specific IgE can be easily performed on young children, but it can be performed only up to 12 antigens in patients younger than 6 years due to insurance coverage. Therefore, it is important to select appropriate antigens for the patients. Appropriate allergens may vary depending on the patient's age, accompanying disease, and residential area, so that detailed history taking is essential for proper allergen selection. In this review, we will discuss considerations for selecting appropriate allergens for clinicians when performing an allergy test on difficult-to-test children under 6 years of age.

Could exhaled breath temperature discriminate the asthma?

No abstract available.

Allergen sensitization and clinical characteristics in young children with atopic dermatitis

PURPOSE: Few studies have demonstrated the effects of aeroallergen sensitization on the development of atopic dermatitis (AD) in young children. This study aimed to investigate the sensitization rate of food and aeroallergens in AD patients under 2 years of age and to compare clinical characteristics between IgE- and non-IgE-mediated AD patients. METHODS: Children aged less than 2 years who had visited CHA Bundang Medical Center from 2013 through 2016 were enrolled. Allergen sensitization was measured by specific IgE levels for common allergens. Detailed information was obtained using an atopy questionnaire. RESULTS: A total of 173 patients were examined, 118 (68.2%) were male patients. The prevalence of aeroallergen sensitization under 1 year of age was 4.8% and increased to 19.5% for children aged 2 years (P=0.005). The mean age (13.6±6.3 months vs. 9.0±5.1 months, P=0.003) and the proportion of children born prematurel (15.4% vs. 2.3%, P=0.013) were higher in the aeroallergen-sensitized group than in nonsensitized group. Sensitization to food allergens between children aged less than 1 year and 2 years appeared to be similar (61.1% vs. 57.1%, P=0.651). There were no significant differences in clinical characteristics between food allergen IgE-mediated and non-IgE-mediated AD children. CONCLUSION: Aeroallergen sensitization increased markedly in AD patients aged 2 years which is about 4 times that of the general population. However, there were no significant differences in clinical manifestations between allergen IgE-mediated and non-IgE-mediated AD children in both food and aeroallergens.

Allergen sensitization and vitamin D status in young Korean children with urticaria

PURPOSE: Urticaria is a common disorder, with a lifetime incidence of approximately 15%–20% of the general population. It is difficult to differentiate urticaria in children because of the similarity in symptoms between acute and chronic urticaria. There is also a lack of studies between vitamin D known as an important role in the immune system and urticaria in children. The present study aimed to assess the characteristics and allergen sensitization of young children diagnosed with urticaria and to evaluate the relationship between their vitamin D status and urticaria. METHODS: We retrospectively reviewed medical records of 218 children diagnosed as having urticaria at CHA and Myongji Hospitals between April 2013 and December 2014. The results of questionnaires and laboratory tests, including specific IgE and serum 25-hydroxy vitamin D concentrations were obtained. RESULTS: Of 218 patients, 118 (54%) were positive for at least 1 allergen and there was no significant difference in the prevalence of sensitization between the acute and chronic urticaria groups. However, the prevalence of polysensitization and sensitization of house dust mites was significantly higher in the chronic urticaria group than in the acute urticaria group (P=0.011 and P=0.029, respectively). Among the urticaria symptoms, an itching sensation was more associated with insufficient vitamin D status in children with urticaria (P=0.034). CONCLUSION: Our results demonstrated that children with chronic urticaria have a higher prevalence of sensitization to house dust mites and polysensitization. Further studies will need to determine whether the supply of vitamin D can improve itching sensation in urticaria children with an insufficient vitamin D status.

Prevalence and Risk Factors of Urticaria With a Focus on Chronic Urticaria in Children

PURPOSE: Limited data is available on the prevalence and risk factors of acute and chronic urticaria in children. Our purpose was to determine the prevalence and identify the risk factors of acute and chronic urticaria in Korean children. METHODS: This population-based study examined 4,076 children (age 4 to 13 years) who were enrolled in the 2015 prospective Seongnam Atopy Project (SAP 2015) in Korea. The parents completed an urticaria questionnaire that included questions regarding the duration, severity, and triggering factors of urticaria. Blood sampling (n=464) was performed to measure vitamin D, total eosinophil count (TEC), and total IgE levels, and skin prick tests (n=503) were done. RESULTS: The prevalences of the life-time, acute, and chronic urticaria were 22.5%, 13.9%, and 1.8% (chronic continuous urticaria, 0.7%; and chronic recurrent urticaria, 1.1%), respectively. Acute urticaria was significantly associated with allergic diseases and parental history of allergy (P<0.001), but chronic urticaria was not associated with these clinical factors. There was no significant difference in the 25-hydroxyvitamin D level between subjects with chronic urticaria and controls (P=0.124). Chronic continuous urticaria was associated with living in a new residence (aOR=2.38, 95% CI=1.02-5.54, P=0.044) and belonging to a family with a high income (aOR=4.24, 95% CI=1.24-14.56, P=0.022). CONCLUSIONS: A total of 1.8% of children were found to have chronic urticaria. Living in a new residence and belonging to a family with a high income increased the risk of chronic continuous urticaria.