Predicting the Outcome of Pediatric Oral Food Challenges for Determining Tolerance Development.

PURPOSE: Despite the risk of anaphylaxis, oral food challenges (OFCs) are performed clinically for various indications, particularly to confirm tolerance development. This study aimed to assess OFCs by relevant indications and build an outcome prediction model to help determine when to perform OFCs in children who are likely to have developed immune tolerance. METHODS: In total, 432 pediatric OFCs were retrospectively analyzed according to indications. Clinical characteristics, serum total immunoglobulin (Ig) E, blood eosinophils, and specific IgE and IgG4 levels for food allergens were noted and compared. Machine learning was utilized to select the most important variables in determining the passage of the OFCs, and prediction models were constructed using the selected variables. RESULTS: OFCs were most commonly performed to confirm tolerance development (number, %; 267, 61.8%). The most common food allergens tested were egg (191, 44.2%) and milk (135, 31.3%). Children who passed the egg challenges for confirming tolerance acquisition had significantly lower egg white-specific IgE level (P = 0.008). Similarly, those who passed milk challenges had significantly lower cow's milk-specific IgE (P = 0.002) and casein-specific IgE levels (P = 0.005). We developed a nomogram to predict the outcome of OFCs to determine the tolerance acquisition with the selected variables; lower food-specific IgE, higher total IgE, and younger age indicated a higher probability of passage. The area under the curve (95% confidence interval) was 0.623 (0.503-0.743) for egg and 0.734 (0.628-0.840) for milk. CONCLUSIONS: Serum total IgE and food-specific IgE combined with age showed trends toward passing OFCs for confirming tolerance development. The constructed model may be used by clinicians as a practical guide for minimizing the risks of OFCs and a timely reintroduction for children with food allergies.

Variation in the Allergenicity of Scrambled, Boiled, Short-Baked and Long-Baked Egg White Proteins.

BACKGROUND: Hen's egg white (HEW) is the most common cause of food allergy in children which induces mild to fatal reactions. The consultation for a proper restriction is important in HEW allergy. We aimed to identify the changes in HEW allergenicity using diverse cooking methods commonly used in Korean dishes. METHODS: Crude extract of raw and 4 types of cooked HEW extracts were produced and used for sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), and ELISA inhibition assays using 45 serum samples from HEW allergic and tolerant children. Extracts were prepared; scrambled without oil for 20-30 seconds in frying pan without oil, boiled at 100°C for 15 minutes, short-baked at 180°C for 20 minutes, and long-baked at 45°C for 12 hours with a gradual increase in temperature up to 110°C for additional 12 hours, respectively. RESULTS: In SDS-PAGE, the intensity of bands of 50-54 kDa decreased by boiling and baking. All bands almost disappeared in long-baked eggs. The intensity of the ovalbumin (OVA) immunoglobulin E (IgE) bands did not change after scrambling; however, an evident decrease was observed in boiled egg white (EW). In contrast, ovomucoid (OM) IgE bands were darker and wider after scrambling and boiling. The IgE binding reactivity to all EW allergens were weakened in short-baked EW and considerably diminished in long-baked EW. In individual ELISA analysis using OVA+OM+ serum samples, the median of specific IgE optical density values was 0.435 in raw EW, 0.476 in scrambled EW, and 0.487 in boiled EW. Conversely, it was significantly decreased in short-baked (0.406) and long-baked EW (0.012). Significant inhibition was observed by four inhibitors such as raw, scrambled, boiled and short-baked HEW, but there was no significant inhibition by long-baked HEW (IC50 > 100 mg/mL). CONCLUSION: We identified minimally reduced allergenicity in scrambled EW and extensively decreased allergenicity in long-baked EW comparing to boiled and short-baked EW as well as raw EW. By applying the results of this study, we would be able to provide safer dietary guidence with higher quality to egg allergic children.

Perspectives and gaps in the management of food allergy and anaphylaxis in the Asia-Pacific Region.

Background: Food allergy (FA), which is a condition that has no effective cure and can result in severe life-threatening allergic reactions, remains a global public health concern; however, little is known about how FAs are currently managed in the Asia-Pacific region. Objective: The main objective of this survey was to evaluate the epidemiology of FA, as well as the availability of resources and practices for management of FA and anaphylaxis by health care providers across Asia. Methods: From June 2022 to September 2022, a questionnaire-based survey comprising 66 questions was electronically sent to member societies of the Asia Pacific Association of Allergy Asthma and Clinical Immunology by using Survey Monkey. Results: A total of 20 responses were received from 15 member countries and territories. Compared with the pediatric data, there was a lack of prevalence data for FA in adults. Except for Australia and Japan, most regions had between 0.1 and 0.5 allergists per 100,000 population and some had fewer than 0.1 allergists per 100,000 population. The perceived rate of FA in regions with a short supply of allergists was high. Although specific IgE tests and oral food challenges were available in all regions, the median wait time for oral food challenges at government facilities was 37 days (interquartile range = 10.5-60 days). Seven regions still relied on prescriptions of ampules and syringes of injectable adrenaline, and adrenaline autoinjectors were not accessible in 4 regions. Oral immunotherapy as FA treatment was available in half of the surveyed countries and territories. Conclusions: Our study offers a cross-sectional evaluation of the management practices for FA in each Asia Pacific Association of Allergy Asthma and Clinical Immunology member country or territory. Urgent actions are required to enhance allergy services, improve the accessibility and affordability of adrenaline autoinjectors, and conduct robust epidemiologic studies.

Clinical Manifestations and Genotype of Primary Ciliary Dyskinesia Diagnosed in Korea: Multicenter Study.

PURPOSE: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder that leads to secondary ciliary dysfunction. PCD is a rare disease, and data on it are limited in Korea. This study systematically evaluated the clinical symptoms, diagnostic characteristics, and treatment modalities of pediatric PCD in Korea. METHODS: This Korean nationwide, multicenter study, conducted between January 2000 and August 2022, reviewed the medical records of pediatric patients diagnosed with PCD. Prospective studies have been added to determine whether additional genetic testing is warranted in some patients. RESULTS: Overall, 41 patients were diagnosed with PCD in 15 medical institutions. The mean age at diagnosis was 11.8 ± 5.4 years (range: 0.5 months-18.9 years). Most patients (40/41) were born full term, 15 (36.6%) had neonatal respiratory symptoms, and 12 (29.3%) had a history of admission to the neonatal intensive care unit. The most common complaint (58.5%) was chronic nasal symptoms. Thirty-three patients were diagnosed with transmission electron microscopy (TEM) and 12 patients by genetic studies. TEM mostly identified outer dynein arm defects (alone or combined with inner dynein arm defects, n = 17). The genes with the highest mutation rates were DNAH5 (3 cases) and DNAAF1 (3 cases). Rare genotypes (RPGR, HYDIN, NME5) were found as well. Chest computed tomography revealed bronchiectasis in 33 out of 41 patients. Among them, 15 patients had a PrImary CiliAry DyskinesiA Rule score of over 5 points. CONCLUSIONS: To our knowledge, this is the first multicenter study to report the clinical characteristics, diagnostic methods, and genotypes of PCD in Korea. These results can be used as basic data for further PCD research.

Natural course of IgE-mediated food allergy in children.

The prevalence of food allergy and food-induced anaphylaxis in children is increasing worldwide. Cow's milk, hen's eggs, and wheat allergies in young children have a more favorable prognosis with a relatively early outgrow, while allergies to peanuts, tree nuts, and seafood are more likely to be persistent. Although our understanding of the mechanism underlying the resolution of food allergy is incomplete, the roles of dendritic cells, regulatory T cells, and regulatory B cells are important. Many past studies on the natural course of food allergy were retrospective analyses of specific study groups, but large-scale population-based prospective studies are now being published. This review summarizes recent studies of the natural course of cow's milk, hen's eggs, wheat, peanuts, tree nuts, soy, sesame, and seafood allergies. The potential factors affecting the natural course of food allergy include symptom severity on ingestion, age at diagnosis, allergic comorbidities, skin prick test reaction size or serum food-specific immunoglobulin (Ig) E levels, changes in sensitization degree, IgE epitope specificity, ratio of food-specific IgE to IgG4, food-specific IgA levels, component-resolved diagnostic profile, diet, gut microbiome, and interventions such as immunotherapy. Since food allergy places a significant burden on patients and their caregivers in daily life, clinicians should be able to provide relevant knowledge on the natural course of food allergy, appropriately evaluate its resolution, and offer therapeutic options whenever possible.

Maternal Posttraumatic Stress Symptoms and Psychological Burden in Mothers of Korean Children With Anaphylaxis.

PURPOSE: Anaphylaxis is a severe allergic reaction that is potentially life-threatening, but post-traumatic stress symptoms (PTSS) in the caregivers of children with anaphylaxis have not been evaluated. This study aimed to investigate the psychological burden on mothers of children with recent anaphylaxis. METHODS: A total of 188 children with recent anaphylaxis was recruited from 13 hospitals in Korea. Validated questionnaires, including the Korean versions of the Beck Anxiety Inventory (K-BAI), the Beck Depression Inventory (K-BDI), and the Impact of Event Scale Revised-Korean version (IES-R-K), were used to evaluate maternal anxiety, depression, and PTSS. RESULTS: The median ages of children and their mothers were 4 and 36 years, respectively. PTSS (IES-R-K ≥ 25) were identified in 56.9% of mothers, and 57.9% of them showed severe PTSS. The proportions of mothers who had anxiety (K-BAI ≥ 22) and depression (K-BDI ≥ 17) were 18.6% and 33.0%, respectively. Multivariable logistic regression analysis indicated that the patient's history of asthma (adjusted odds ratio [aOR], 5.46; 95% CI, 1.17-25.59) and the presence of central nervous symptoms (aOR, 3.27; 95% CI, 1.07-9.96) were associated with PTSS. Age of 2 or older (aOR, 2.87; 95% CI, 1.10-7.52) and eggs, milk, or wheat as the cause of anaphylaxis (aOR, 2.87; 95% CI, 1.10-7.52) increased the risk of severe PTSS. CONCLUSIONS: The rate of PTSS among mothers of children with recent anaphylaxis was high at 56.9%. Clinicians who care for pediatric anaphylaxis patients should be aware of the psychological burden on their caregivers.

A partially hydrolyzed whey formula provides adequate nutrition in high-risk infants for allergy.

BACKGROUND/OBJECTIVES: Hydrolyzed formula is often fed to infants with gastrointestinal or immune issues, such as malabsorption or cow's milk allergy, because enzymatic treatment has rendered it more digestible and less allergenic than standard cow's milk formula (SF). Partially hydrolyzed formula (PHF) should be considered for those infants who are intolerant to extensively hydrolyzed formula. However, there are concerns about the nutritional insufficiencies of PHF. We aimed to evaluate the effects of PHF on the growth and health indicators in infants who were at high-risk of allergic disease and potential candidates for consuming PHF. SUBJECTS/METHODS: A total of 83 infants aged 0-2 mon with a family history of allergies were assigned to consume either PHF or SF until 24 weeks of age. Anthropometric measures were obtained at baseline, 12 weeks, and 24 weeks; blood samples were drawn and evaluated at the end of the study. RESULTS: No significant differences were observed in weight, height, and weight-for-height at any time point in each sex between the PHF and SF groups. At 24 weeks of age, the weight-for-age and height-for-age z-scores of the SF group were higher than those of the PHF group, but there was no significant difference in the weight-for-height z-score. There were no significant differences in levels of white blood cells, hemoglobin, ferritin, protein, albumin, aspartate aminotransferase, alanine aminotransferase, eosinophil cationic protein, and immunoglobulin E. CONCLUSIONS: In this study, there were no differences in growth and blood panels between the infants consuming PHF or SF. Therefore, infants who are unable to tolerate SF can be fed PHF without nutritional concerns about growth.

Clinical Characteristics of Atopic Dermatitis in Korean School-Aged Children and Adolescents According to Onset Age and Severity.

BACKGROUND: Atopic dermatitis (AD) is a heterogeneous disease with different age of onset, disease course, clinical symptoms, severity, and risk of comorbidity. The characteristics of children with AD also vary by age or country. However, little is known about the clinical characteristics of AD in Korean school-aged children and adolescents. Furthermore, there are few studies on phenotypic differences according to onset age. This study aimed to explore the clinical characteristics and phenotypes according to onset age and severity of AD in children and adolescents in Korea. METHODS: AD patients aged 6-18 years who presented to 18 hospitals nationwide were surveyed. The patients were examined for disease severity by pediatric allergy specialists, and data on history of other allergic diseases, familial allergy history, onset age, trigger factors, lesion sites, treatment history and quality of life were collected. The results of the patient's allergy test were also analyzed. The patients were classified into infancy-onset (< 2 years of age), preschool-onset (2-5 years of age), and childhood-onset (≥ 6 years of age) groups. Study population was analyzed for clinical features according to onset-age groups and severity groups. RESULTS: A total of 258 patients with a mean age of 10.62 ± 3.18 years were included in the study. Infancy-onset group accounted for about 60% of all patients and presented significantly more other allergic diseases, such as allergic rhinitis and asthma (P = 0.002 and P = 0.001, respectively). Food allergy symptoms and diagnoses were highly relevant to both earlier onset and more severe group. Inhalant allergen sensitization was significantly associated with both infancy-onset group and severe group (P = 0.012 and P = 0.024, respectively). A family history of food allergies was significantly associated with infancy-onset group (P = 0.036). Severe group was significantly associated with a family history of AD, especially a paternal history of AD (P = 0.048 and P = 0.004, respectively). Facial (periorbital, ear, and cheek) lesions, periauricular fissures, hand/foot eczema, and xerosis were associated with infancy-onset group. The earlier the onset of AD, the poorer the quality of life (P = 0.038). Systemic immunosuppressants were used in only 9.6% of the patients in the severe group. CONCLUSION: This study analyzed the clinical features of AD in Korean children and adolescents through a multicenter nationwide study and demonstrated the phenotypic differences according to onset age and severity. Considering the findings that the early-onset group is more severe and accompanied by more systemic allergic diseases, early management should be emphasized in young children and infants.

Prediction of Food Allergens Sensitization Based on History Taking Technique in Young Children.

BACKGROUND: The diagnosis of food allergies needs to be confirmed through an oral food challenge (OFC). However, specific immunoglobulin E (sIgE) concentrations analyzed by serological tests are also helpful in determining OFC items and predicting the presence of allergic reactions. Unfortunately, there is a limit to the number of antigens that can be simultaneously evaluated at one time. The purpose of this study was to analyze the possibility of detecting sIgE antibodies against food using clues in self-reported food allergy symptoms. METHODS: Medical records of 377 patients aged 3 years or younger were collected for egg white-, cow's milk-, walnut- and soybean-sIgE sensitization, and related clinical history. Each clinical history was classified into class 1: direct-isolated intake resulting in anaphylaxis or hives with consistent clincical history; class 2a: class 1 with inconsistency; class 2b: indirect-mixed intake resulting in anaphylaxis or hives regardless of consistency; class 2c: direct/indirect-isolated/mixed intake resulting in itching without hives, vomiting, or diarrhea with consistent clincical history; or class 3: class 2c with inconsistency or asymptomatic to direct, isolated exposure. RESULTS: The area under the curve (AUC) of class 1 for cow's milk was 0.790, and the accuracy was 78.0%. The AUC of class 1 and 2 for egg white was better than that of class 1 (0.750), and the accuracy rate was 77.6%. The AUCs of class 1 for walnut and soybean were 0.775 and 0.662, respectively. CONCLUSION: In conclusion, sIgE sensitization to foods could be predicted by the combination of exposure and selfreported symptoms in children under 3 years of age.

A Preliminary Study on Cross-Reactivity of Heat-Treated Quail and Hen's Egg White Proteins in Young Children.

We investigated the effects of different types of heat treatments on hen's egg white (HEw) and quail egg white (QEw) proteins and their cross-reactivity in young children. Crude extracts of raw and water-boiled HEw and QEw and commercially developed stone-baked HEw were prepared. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was then performed. Patients diagnosed with HEw allergy were enrolled, and pooled sera were tested with each extract in an enzyme-linked immunosorbent assay (ELISA)-inhibition test. A skin prick test (SPT) and oral food challenge (OFC) were also performed. The median age of 12 patients was 2.5 years. SDS-PAGE results revealed strongly stained bands for the ovomucoid of boiled HEw and QEw, while stone-baked HEw displayed remarkable changes for all protein fractions. In the ELISA-inhibition test, pre-incubation of the sera led to a profound decrease, moderate decrease, and minimal decrease in the amount of IgE binding to boiled and raw HEw, boiled and raw QEw, and stone-baked HEw proteins, respectively. SPTs and OFC demonstrated cross-reactivity values of 41.7% (5/12) and 16.7% (2/12) for boiled QEw and stone-baked HEw, respectively. We observed moderate cross-reactivity between QEw and HEw. Boiling had a limited effect on altering egg allergenicity. Commercially developed, stone-baked HEw can be an alternative food for children with HE allergy.

Component resolved diagnosis of walnut allergy in young children: Jug r 1 as a major walnut allergen.

BACKGROUND: Walnuts (WN) are one of the main causes of tree nut allergies. However, the potential value of component resolved diagnosis (CRD) for WN allergy is controversial. OBJECTIVE: We analyzed the clinical and immunological features of clinical WN allergy and the usefulness of CRD in young children. METHODS: Forty-one participants with a history of ingesting WN who were assessed for serum-specific IgE to WN (WNsIgE) using CRD (ImmunoCAP ISAC 112) at the Department of Pediatrics in Ajou University Hospital were enrolled and their demographic profiles, clinical symptoms, and laboratory findings were evaluated. RESULTS: A total of 32 patients were diagnosed with clinical WN allergy, of which 31 had specific immunoglobulin E antibodies to Jug r 1 (Jug r1-sIgE). The Jug r 1-sIgE levels were higher in WN-allergic patients than in WN-tolerant patients and significantly higher in patients with anaphylaxis than in the WN-tolerant patients. Receiver-operating characteristic curves demonstrated that the Jug r 1-sIgE level was much better in discriminating between clinical WN allergy and WN tolerance in young children than the WN-sIgE level. CONCLUSIONS: Jug r 1 is the major component allergen in young children with clinical WN allergy. To measure Jug r 1-sIgE appears to be a promising approach for both diagnosis and predicting severity in young children with a history of suspected WN allergy.

IgE recognition profile of aeroallergen components in young children sensitized to dogs.

BACKGROUND: Pet ownership is increasing rapidly and as growing numbers of dogs in household, clinicians are facing more allergic patients and so as in young children. OBJECTIVE: This study aims to profile the IgE recognition patterns to aeroallergen components in young children sensitized to dogs. METHODS: Through retrospective chart reviews, we evaluated the clinical, environmental, and laboratory findings of patients sensitized to dogs in early life. We further evaluated specific IgE to dog component allergens (Can f 1, Can f 2, and Can f 3) and other aeroallergens using a microarray. RESULTS: The median age of 28 patients sensitized to dogs (dog-specific IgE ≥ 0.35 kU/L; 0.38-101 kU/L) was 61 months and underlying diseases included doctor diagnosed atopic dermatitis (n = 17), asthma (n = 7), and allergic rhinitis (n = 5). Twenty patients (71.4%) had experienced self-reported dog allergy and 70.0% of them were symptomatic after exposed to dogs from others. Component-resolved diagnosis was performed on 18 patients. Can f 1 positivity was the most common (77.8%) but had no value in symptom prediction. The most common cosensitized aeroallergen was house dust mites (44.5%). The symptomatic group tended to be poly-sensitized to Can f 1, Can f 2, and Can f 3. CONCLUSION: Can f 1 was dominantly detected and poly-sensitized to Can f 2 and/or Can f 3 simultaneously tend to develop hypersensitivity to dogs in young children. Most of them were exposed to dogs not living with.

A multicenter anaphylaxis registry in Korea: Clinical characteristics and acute treatment details from infants to older adults.

BACKGROUND: Although the prevalence of anaphylaxis is increasing worldwide, the large-scale studies in Asia evaluating anaphylaxis in all age groups are limited. We aimed to collect more precise and standardized data on anaphylaxis in Korea using the first multicenter web-based registry. METHODS: Twenty-two departments from 16 hospitals participated from November 2016 to December 2018. A web-based case report form, designed by allergy specialists, was used to collect anaphylaxis data. RESULTS: Within the 2-year period, 558 anaphylaxis cases were registered. The age of registered patients ranged from 2 months to 84 years, and 60% were aged <18 years. In children and adolescents, foods (84.8%) were the most common cause of anaphylaxis, followed by drugs (7.2%); in adults, drugs (58.3%) were the most common cause, followed by foods (28.3%) and insect venom (8.1%). The onset time was ≤10 min in 37.6% of patients. Among the 351 cases registered via the emergency department (ED) of participating hospitals, epinephrine was administered to 63.8% of patients. Among those receiving epinephrine in the ED, 13.8% required 2 or more epinephrine shots. Severe anaphylaxis accounted for 23.5% cases (38.1% in adults; 13.7% in children); patients with drug and insect venom-induced anaphylaxis had higher rates of severe anaphylaxis. CONCLUSION: This multicenter registry provides data on anaphylaxis for all age groups for the first time in Asia. The major causes and severity of anaphylaxis were remarkably different according to age group, and the acute treatment features of anaphylaxis in the EDs were examined in detail.

A randomized trial of Lactobacillus rhamnosus IDCC 3201 tyndallizate (RHT3201) for treating atopic dermatitis.

BACKGROUND: Probiotic therapies, mainly live bacteria, have been proven to be effective in treating atopic dermatitis (AD) with some controversies. Killed probiotics or postbiotics would have immunomodulatory effect in allergic diseases including AD. This study was performed to evaluate the therapeutic effect and safety of tyndallized Lactobacillus rhamnosus (IDCC 3201, isolated from the feces of a Korean breastfed infant, repeated heat-treated and incubated, RHT3201) in children with AD. METHODS: In a randomized, double-blind, placebo-controlled study, RHT3201 at a dose of 1.0 × 1010  CPU/d or placebo was given in children (aged 1-12 years) with moderate AD for 12 weeks. SCORing of AD (SCORAD) scores, allergic inflammatory markers, and safety parameters were evaluated. RESULTS: For evaluating the therapeutic effects of RHT3201, 33 subjects in each group were analyzed. The change of SCORAD total score at 12 weeks (primary outcome) from baseline was significantly greater in the RHT3201 group (-13.89 ± 10.05) compared to the control group (-8.37 ± 9.95). Levels of eosinophil cationic protein (ECP) and interleukin (IL)-31 showed tendency to decrease in the RHT3201 group and significant decreases in subgroup analysis in AD for ≥50 months. For safety analysis, a total of 100 subjects (50 in the treated group and 50 in the control group) were evaluated, and there were no significant differences in safety parameters between two groups. CONCLUSION: In children with moderate AD, oral administration of RHT3201 showed the therapeutic effect on AD, the effects in part correlated with decrement of ECP and IL-31, and the effect was more remarkable in subgroup analysis.

Clinical and Laboratory Findings of Barley Allergy in Korean Children: a Single Hospital Based Retrospective Study.

BACKGROUND: Barley is a grain that is consumed in various forms in Asia. Studies on barley allergy are limited to a few case reports about hypersensitivity reactions to beer, but there is no barley allergy study in children. This study aimed to identify the phenotype and immunologic findings in Korean children with barley allergy. METHODS: Forty-two participants with a history of ingesting barley who underwent serum specific immunoglobulin E to barley (barley-sIgE) assay at the Department of Pediatrics in Ajou Medical Center were enrolled through a retrospective analysis of medical records from March 2008 to February 2018. The demographic characteristics, symptoms, and immunologic parameters of the patients were assessed. RESULTS: Twenty subjects presented with clinical barley allergy (B-allergic group), and 22 were atopic controls without allergic reactions after the ingestion of barley (B-tolerant group). The median ages of the B-allergic and B-tolerant groups were 1 and 3 years, respectively. In the B-allergic group, the cutaneous system (90.0%) was most frequently affected, followed by the respiratory system (40.0%). Anaphylaxis was observed in 35.0% of the B-allergic group. The median level of barley-sIgE was 13.90 kUA/L (range, 0.14-101.00 kUA/L) in the B-allergic group, and this value was significantly higher (P < 0.001) than that of the B-tolerant group (0.30 kUA/L; range, 0.01-24.40 kUA/L), with an optimal cutoff level of 1.24 kUA/L (sensitivity, 85.0%; specificity, 86.4%). A positive correlation was found between the serum levels of barley-sIgE and wheat-sIgE in the B-allergic group with clinical wheat allergy. CONCLUSION: Barley is an important allergen for children in Korea. This study showed the clinical characteristics of barley allergy and suggested optimal cut-off levels of barley-sIgE for clinical barley allergy. Clinically, cross-reactivity or co-sensitization is often observed between barley and wheat.

Clinical characteristics and etiologies of bronchiectasis in Korean children: A multicenter retrospective study.

BACKGROUND: Bronchiectasis is a chronic pulmonary disease characterized by progressive and irreversible bronchial dilatation. The aim of the present study was to investigate the etiologies and clinical features of bronchiectasis in Korean children. METHODS: We performed a retrospective review of the medical records for children diagnosed with bronchiectasis between 2000 and 2017 at 28 secondary or tertiary hospitals in South Korea. RESULTS: A total of 387 cases were enrolled. The mean age at diagnosis was 9.2 ±â€¯5.1 years and 53.5% of the patients were boys. The most common underlying cause of bronchiectasis was preexisting respiratory infection (55.3%), post-infectious bronchiolitis obliterans (14.3%), pulmonary tuberculosis (12.3%), and heart diseases (5.6%). Common initial presenting symptoms included chronic cough (68.0%), recurrent pneumonia (36.4%), fever (31.1%), and dyspnea (19.7%). The most predominantly involved lesions were left lower lobe (53.9%), right lower lobe (47.1%) and right middle lobe (40.2%). No significant difference was observed in the distribution of these involved lesions by etiology. The forced expiratory volume in 1 s (FEV1) levels were lowest in cases with interstitial lung disease-associated bronchiectasis, followed by those with recurrent aspiration and primary immunodeficiency. CONCLUSIONS: Bronchiectasis should be strongly considered in children with chronic cough and recurrent pneumonia. Long-term follow-up studies on pediatric bronchiectasis are needed to further clarify the prognosis and reduce the disease burden in these patients.

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.

A population-based epidemiological study of anaphylaxis using national big data in Korea: trends in age-specific prevalence and epinephrine use in 2010-2014.

BACKGROUND: Previous reports on anaphylaxis in Asia are limited to relatively small-scale studies. We performed this study to identify the nationwide prevalence of anaphylaxis and epinephrine prescription rates by age groups. METHODS: The total number of patients, yearly and overall prevalence, percentage of emergency department visits, and epinephrine prescription rates were calculated for patients diagnosed with anaphylaxis based on the Korean National Health Insurance database from 2010 to 2014. RESULTS: The mean prevalence of anaphylaxis in Korea was 26.23 (95% confidence interval, CI 25.78-26.68) per 100,000 person-years during the 5 years. It increased from 20.55 (95% CI 20.15-20.10) in 2010 to 35.33 (95% CI 34.81-35.85) per 100,000 person-years in 2014. The average prevalence was > 35 per 100,000 person-years among 50-69 year-olds, and the mean crude prevalence in children was 22.3 (0-2 years), 17.3 (3-6 years), 12.1 (7-12 years), and 14.9 (13-17 years) per 100,000 person-years, respectively. The overall prevalence increased 1.7-fold, with the highest rate of increase in 0-2 years of age. The overall percentage of emergent anaphylaxis patients was 88.4%, and the prevalence of emergent anaphylaxis increased from 18.63 (95% CI 18.25-19.01) to 31.28 (95% CI 30.79-31.77) per 100,000 person-years. In-hospital epinephrine prescription rate increased from 31.5 to 39.7%. CONCLUSIONS: The mean prevalence of anaphylaxis in Korea was 26.2 per 100,000 person-years during the study period. The total number of anaphylaxis patients increased 1.7-fold from 2010 to 2014, with the most noticeable increment being in young children.

Immunoglobulin E-binding Proteins of Cooked Walnuts in Korean Children.

PURPOSE: The immunological characteristics of young Korean children with walnut (WN) allergy and the influence of different cooking methods on WN proteins have not been evaluated to date. This study aimed to evaluate the major WN allergens identified among Korean children, together with changes in WN antigenicity caused by common cooking methods. METHODS: We enrolled children under the age of 13 years with WN serum-specific immunoglobulin (Ig) E concentrations. The protein fractions of dry-fried and boiled WN extracts were compared with those of raw WNs using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), 2-dimentional gel electrophoresis (2DE) and a proteomic analysis using electrospray ionization (liquid chromatography-mass spectrometry [LC-MS]). An immunoblotting analysis was conducted to examine IgE reactivity toward raw WNs using serum samples from 6 children with a clinical WN allergy. To determine the processed WN proteins with IgE-binding capacity, a 2D-immunoblotting analysis was performed using the pooled sera of 20 WN-sensitized children. RESULTS: Protein bands from raw WNs were identified at 9, 16, 28, 52, 58, and 64 kDa via SDS-PAGE. The 9- and 16-kDa protein bands were enhanced by boiling, whereas the 52- and 64-kDa bands were considerably diminished. On LC-MS analysis, of the 66 IgE-binding proteins present in raw WNs, 57 were found in dry-fried WNs, but only 4 in boiled WNs. The sera of 5 out of 6 participants reacted with the 52-kDa protein bands and those of 4 out of 6 participants reacted with the 16- and 28-kDa protein bands, respectively. Meanwhile, a 2D-immunoblotting result confirmed the presence of different binding patterns among children who consumed cooked WNs. CONCLUSIONS: The protein profile of boiled WNs is substantially different from that of raw WNs. However, 4 proteins including prolamins remained stable after dry-frying or boiling. Further studies are needed to evaluate the clinical relevance of these findings.