Cross-reactivity of Can f 1 with Syrian hamster and Fel d 1 in children.

Introduction and objectives: With increasing pet allergies among pediatric patients, the need for precise environmental care is increasing. We investigated the clinical, immunological, and environmental characteristics of pediatric patients sensitized to a dog to evaluate the cross-antigenicity of canine lipocalin Can f 1 with feline lipocalin Fel d 1 and Syrian hamster extract.Materials and methods: The protein fractions of the processed and commercial Syrian hamster extracts were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An enzyme-linked immunosorbent assay (ELISA) inhibition test was performed on Can f 1, Fel d 1, and processed Syrian hamster extract, and the antigen-specific immunoglobulin E (IgE)-binding capacity for each antigen was analyzed using serum samples from patients.Results: Twelve of 19 patients with a median age of 40.5 months were symptomatic when exposed to dogs. Eleven (91.7%) patients showed a positive IgE response to Can f 1. Two patients were positive for Fel d 1-specific IgE antibody, and one was positive for hamster-specific IgE antibody. SDS-PAGE confirmed the presence of different patterns of protein bands between the commercial and processed hamster extracts. There was no cross-antigenicity among Can f 1, Fel d 1, and processed Syrian hamster extract.

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.

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.

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.

Clinical Significance of Component Allergens in Fagales Pollen-Sensitized Peanut Allergy in Korea

PURPOSE: Clinical features of peanut allergy can range from localized to systemic reactions. Because peanut and birch pollen have cross-reactivity, peanut can lead to localized allergic reaction in Fagales pollen-sensitized oral allergy syndrome (OAS) patients without peanut sensitization per se. The purpose of this study was to discriminate true peanut food allergy from cross-reactive hypersensitivity in birch-sensitized peanut allergy. METHODS: Birch-sensitized (n=81) and peanut anaphylaxis patients (n=12) were enrolled. Peanut-related allergic reactions and sensitization profiles were examined. Specific IgE to Fagales tree pollens (birch, oak), peanut, and their component allergens (Bet v 1, Bet v 2, Ara h 1, Ara h 2, Ara h 3, Ara h 8, and Ara h 9) were evaluated. Based on these specific IgEs and clinical features, the patients were classified into 4 groups: group 1 (Fagales pollen allergy without OAS), group 2 (Fagales pollen allergy with OAS), group 3 (OAS with peanut anaphylaxis), and group 4 (peanut anaphylaxis). RESULTS: After peanut consumption, one-third of OAS patients experienced oral symptoms not associated with peanut sensitization. Ara h 1 or Ara h 2 was positive in peanut anaphylaxis patients, whereas Ara h 8 was positive in OAS patients. There were 4 patients with both peanut anaphylaxis and OAS (group 3). Both Ara h 2 and Ara h 8 were positive in these patients. Foods associated with OAS in Korea showed unique patterns compared to Westernized countries. CONCLUSIONS: Ara h 2 and Ara h 8 may be important component allergens for discriminating peanut allergy.

Clinical and laboratory findings of childhood buckwheat allergy in a single tertiary hospital / 소아과

PURPOSE: Buckwheat allergy is one of the most severe types of food allergy in some countries, especially among children. However, few studies have investigated this condition. The aim of this study was to report the clinical and laboratory findings in Korean children with buckwheat allergy. METHODS: Thirty-seven subjects, aged 1 to 14 years, were enrolled by retrospective medical record review from January 2000 through May 2015 at the Department of Pediatrics in Ajou University Hospital. The demographic profile, previous exposure to buckwheat pillows, clinical symptoms, and laboratory findings of each subject were recorded. RESULTS: Twenty-six of the 37 children had immediate-type allergic symptoms to buckwheat, while 11 subjects were tolerant to buckwheat. Seventeen out of 26 buckwheat allergic children (65.4%) had anaphylaxis. The median buckwheat specific IgE level in the buckwheat allergic group (7.71 kU(A)/L) was significantly higher (P<0.001) than in the buckwheat tolerant group (0.08 kU(A)/L) with an optimal cutoff value of 1.27 kU(A)/L (sensitivity 84.6%, specificity 100%). When adjusted for age, the difference between the 2 groups showed no statistical significance (P=0.063). In subjects who had anaphylaxis, buckwheat-specific IgE levels ranged from 0.37 to 100 kUA/L. CONCLUSION: Almost two-thirds of buckwheat-allergic children had anaphylaxis, and a wide-range of buckwheat specific IgE levels were observed in these children. Anaphylaxis occurred in a subject with a remarkably low IgE level (0.37 kU(A)/L).