Background The effect of diet on allergic rhinitis (AR), its severity in children, and whether it modifies AR depending on genetic susceptibility are unknown. We investigated the association between dietary patterns and AR in school children and the influence of diet on AR according to a genetic risk score (GRS). Methods Totally, 435 7-year-old school children were recruited from the Panel Study on Korean Children. We used dietary patterns (vegetable, sugar, and meat) and dietary inflammatory index (DII) as dietary parameters. AR and its severity were defined by questionnaires about treatment in the previous 12 months and the Allergic Rhinitis and its Impact on Asthma (ARIA) guideline, respectively. A GRS was calculated using 6 single nucleotide polymorphisms for allergic diseases. Results A vegetable diet containing a lot of anti-inflammatory nutrients and higher vitamin D level in blood were negatively correlated, while DII was positively correlated with triglyceride level and triglyceride/HDL cholesterol. Vegetable diet (aOR, 95% CI = 0.73, 0.58-0.94) and DII (1.13, 1.01-1.28) were associated with AR risk. In particular, a high-vegetable diet resulted in a lower risk of mild and persistent AR (aOR, 95% CI = 0.24, 0.10-0.56) while a high DII represented a higher risk (2.33, 1.06-5.10). The protective effect of vegetable diet on AR appeared only among children with a lower GRS (adjustedP = .018). Conclusions A vegetable dietary pattern characterized by high intake of anti-inflammatory nutrients and higher vitamin D level in blood might be associated with a lower risk of mild and persistent AR. This beneficial effect is modified by a genetic factor.

Purpose: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. Methods: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. Results: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio (aOR), 5.26; 95% confidence interval [CI], 1.77-15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40-40.74). Conclusions: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.

BackgroundAlthough bronchial responsiveness (BR) is usually categorized as normal or hyperresponsive to aid the diagnosis of asthma, it exists on a continuous spectrum, not in a dichotomous manner. We aimed to evaluate the distribution profile of BR in a generalpopulation of 7-year-olds. MethodsIn 2015, 7-year-old Korean children from a nationwide birth cohort study visited regional study hospitals for skin prick test, standard spirometry, and bronchial provocation to establish reference values for the general population. Their BR degrees were categorized into five ordered groups: hyperresponsive BRs were classified into group 1 (provocative concentration (PC) of methacholine causing a 20% fall in forced expiratory volume in 1second [FEV1], PC20 of <4mg/mL) and group 2 (PC20 of >= 4mg/mL and <16mg/mL), and nonresponsive BRs were categorized into group 3 (final FEV1 percentage fall after inhaling 16mg/mL of methacholine [FEV1%fall] of >15% and <= 20%), group 4 (FEV1%fall of >10% and <= 15%), and group 5 (FEV1%fall of <= 10%). ResultsIn total, 559 subjects finished all tests reliably. Groups 1 and 2 comprised 10.0% and 15.7% of the total population, respectively. Groups 3, 4, and 5 comprised 14.7%, 18.4%, and 41.1%, respectively. As the group number increased, the proportion of those with recent wheezing and those with indoor allergen sensitization decreased (P for trend=0.001 and P for trend<0.001, respectively), and the baseline FEV1/FVC increased (P for trend<0.001) ConclusionBR of the 7-year-olds in the general population, while showing a wide distribution across phenotypes, is associated with allergic symptoms, negatively correlated with baseline lung function and positively correlated with indoor allergen sensitization.

Purpose: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. Methods: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians' medical records. Results: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n = 109) currently had at least 1 dog and 2.5% (n = 34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29-13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65-18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54-26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. Conclusion: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.

Sensitization plays important roles in the development of asthma and AR in children. We elucidated the association between sensitization patterns and allergic diseases. A cohort of 548 children was enrolled from the Panel Study of Korean Children (PSKC) study. Skin prick tests for 18 common allergens, blood tests, and methacholine bronchial challenge tests were performed at age 7. The Korean version of International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to evaluate the presence of allergic diseases. The sensitization rate was 46.4%. Sensitization to indoor allergens (Der f, Dermatophagoides pteronyssinus [Der p], cat epithelium, dog dander, cockroach) showed an association with symptoms of asthma (adjusted odds ratio [aOR], 2.39; 95% confidence intervals [95% CIs], 1.10-5.23) and allergic rhinitis (AR, aOR 2.08, 95% CIs 1.42-3.06) in the preceding 12 months. In contrast, sensitization to outdoor allergens (grass mixture, alder, birch, oak, Japanese hop, Mugwort, ragweed, hazel) was associated with AR diagnosis only (aOR 2.40, 95% CIs 1.30-4.41). The number of sensitized allergens was associated with a lifetime diagnosis and with symptoms in the preceding 12 months of AR and asthma, but not with BHR. A higher degree of sensitization to indoor and outdoor allergens was associated with symptoms in the preceding 12 months of asthma and AR. The sensitization patterns including allergen type, number, and degree of sensitization are helpful for interpreting the association between sensitization patterns and asthma/AR and identifying the pathophysiologies and diverse phenotypes of allergic diseases.

BACKGROUNDSensitization is associated with the exacerbation, severity, and prognosis of allergic diseases in children OBJECTIVE: We characterized the association between sensitization patterns and allergic diseases.METHODSA cohort of 548 children was enrolled from Panel Study of Korean Children (PSKC) study. Skin prick tests (SPTs) for 18 common allergens, blood tests, and methacholine bronchial challenge tests were performed at age 7. The Korean version of International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used.RESULTSThe sensitization rate on SPTs was 46.4%. Sensitization to indoor allergens showed an association with symptoms of asthma (adjusted odds ratio [aOR], 2.39; 95% confidence intervals [95% CIs], 1.10-5.23), allergic rhinitis (AR, aOR 2.08, 95% CIs 1.42-3.06), and atopic dermatitis (AD, aOR 2.36, 95% CIs 1.24-4.50) in the preceding 12 months. In contrast, sensitization to outdoor allergens was associated with AR diagnosis only (aOR 2.40, 95% CIs 1.30-4.41). The number of sensitized allergens was associated with a lifetime diagnosis and symptoms in the preceding 12 months of AR and asthma, but not with AD or BHR. A higher degree of sensitization to indoor allergens was associated with symptoms in the preceding 12 months of asthma, AR, AD, and that for outdoor allergens was associated with symptoms in the prior 12 months of asthma and AR.CONCLUSIONThe sensitization patterns including allergen type, number, and degree of sensitization are helpful for interpreting the association between sensitization and allergic diseases and identifying the pathophysiologies and diverse phenotypes of allergic diseases.

Although allergic rhinitis(AR) has a large impact on the patient's quality of life, little is known about the risk factors and comorbidities associated with its phenotype in children. The aim of this study was to assess risk factors and comorbidities of AR according to phenotype from a birth cohort study. We enrolled 1,577 children at age 7 years were followed at 2015 from the Panel Study of Korean Children(PSKC) study which is a general population based birth cohort study. Skin prick test was performed on 642 children. Risk factors were analyzed by dividing into four phenotypes according to ARIA guidelines. Prevalence of mild and moderate to severe AR was 37.2% and 8.8%, respectively. Regardless of severity of AR, current AR was highly associated with history of asthma diagnosis and family history of allergic diseases. Recent use of analgesics or pyretics (aOR, 2.32; 95% CI, 1.03-5.24) and current cat ownership (aOR, 10.18; 95% CI, 1.46-71.23) were associated with the risk of mild persistent AR. Sensitization to Der P (aOR, 2.75; 95% CI, 1.18-6.38), Japanese hop (aOR, 5.16; 95% CI, 1.51-17.59) and cat (aOR, 5.28; 95% CI, 1.17-23.63) increased the risk of moderate to severe persistent AR. Whereas mild-persistent AR was associated with sensitization to Alternaria (aOR, 6.81; 95% CI, 1.03-45.03). Children with moderate to severe AR had a higher risk of current asthma and bronchial hyperresponsiveness compared to children with mild AR. Sensitization to inhalant allergen, comorbidities of asthma and bronchial hyperresponsiveness are associated with moderate to severe AR in children.

Background A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. Methods Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. Results The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). Conclusions BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.