Whole lung lavage with granulocyte macrophage colony-stimulating factor inhalation in children with pulmonary alveolar proteinosis: A case report

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by hypoxemic respiratory failure due to the accumulation of lipoproteinaceous material in alveolar macrophages and alveoli. It has been reported that granulocyte macrophage colony-stimulating factor (GM-CSF) inhalation or whole lung lavage significantly improves the disease state. We present a case of 17-year-old female diagnosed with PAP and treated with both GM-CSF inhalation and whole lung lavage. Her symptoms, imaging findings, and pulmonary function tests improved after these treatments. Therefore, combined treatments of whole lung lavage and subsequent GM-CSF inhalation should be considered a treatment option for children and adolescents.

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), preschoolonset (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 infancyonset 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.

Risk Factors and Comorbidities Associated With the Allergic Rhinitis Phenotype in Children According to the ARIA Classification

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.

Antibiotics-Induced Dysbiosis of Intestinal Microbiota Aggravates Atopic Dermatitis in Mice by Altered Short-Chain Fatty Acids

PURPOSE: Alterations in the intestinal microbiota in early life affects the development of atopic dermatitis (AD) in humans. This study aimed to further investigate the effects of gut dysbiosis in early life in an ovalbumin (OVA)-induced mouse model of AD. METHODS: The AD mouse model was developed by serial OVA sensitization and mice were treated with an antibiotic cocktail in their drinking water for 2 weeks before primary sensitization. Probiotics (Lactobacillus rhamnosus, 1 × 10⁹ CFU) or 100 µL of fresh fecal supernatant were orally administered daily from 1 week before the first sensitization until the end of the study. RESULTS: The AD mice which received antibiotics had significantly aggravated phenotypes, including clinical score, transepidermal water loss, and histopathology, compared to those treated with healthy feces or probiotics. Total systemic immunoglobulin E production and skin interleukin (IL) 4 levels were significantly increased in the antibiotic-treated mice compared to the other groups. Antibiotic treatment also increased the levels of IL17 and group 3 innate lymphoid cells (ILC3) in the gut and significantly suppressed the production of short-chain fatty acids (SCFAs) and decreased the number FOXP3⁺ cells. CONCLUSIONS: Our results suggest that the status of the gut microbiota in early life in the mouse may play a crucial role in AD development through intestinal SCFA production through regulate the numbers of CD4⁺IL17⁺/CD4⁺FOXP3⁺ regulatory T cells and ILC3s.

NOTCH1 Pathway is Involved in Polyhexamethylene Guanidine-Induced Humidifier Disinfectant Lung Injuries

0.2 and p<0.05. NOTCH1 was identified as a candidate network hub gene in cases. NOTCH1 transcripts significantly increased in lung tissues from HDLI cases compared to unexposed controls (p=0.05). NOTCH1 may play an important role in pulmonary fibrosis of HDLI.

Imbalance of Gut Streptococcus, Clostridium, and Akkermansia Determines the Natural Course of Atopic Dermatitis in Infant

PURPOSE: The roles of gut microbiota on the natural course of atopic dermatitis (AD) are not yet fully understood. We investigated whether the composition and function of gut microbiota and short-chain fatty acids (SCFAs) at 6 months of age could affect the natural course of AD up to 24 months in early childhood.METHODS: Fecal samples from 132 infants were analyzed using pyrosequencing, including 84 healthy controls, 22 transient AD and 26 persistent AD subjects from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) birth cohort. The functional profile of the gut microbiome was analyzed by whole-metagenome sequencing. SCFAs were measured using gas chromatography-mass spectrometry.RESULTS: Low levels of Streptococcus and high amounts of Akkermansia were evident in transient AD cases, and low Clostridium, Akkermansia and high Streptococcus were found in children with persistent AD. The relative abundance of Streptococcus positively correlated with scoring of AD (SCORAD) score, whereas that of Clostridium negatively correlated with SCORAD score. The persistent AD group showed decreased gut microbial functional genes related to oxidative phosphorylation compared with healthy controls. Butyrate and valerate levels were lower in transient AD infants compared with healthy and persistent AD infants.CONCLUSIONS: Compositions, functions and metabolites of the early gut microbiome are related to natural courses of AD in infants.

Risk factors for the development of asthma symptoms in children with allergic rhinitis

Purpose@#Both allergic rhinitis and asthma are considered one airway disease, which interacts with each other in disease onset and symptom worsening. We evaluated factors developing new or persistent asthma symptoms in elementary school children with allergic rhinitis. @*Methods@#We selected 343 children aged 6 to 7 years who had rhinitis symptoms within 12 months and allergic sensitization on skin prick tests among 2,491 elementary school children. The questionnaires on symptoms, medical history and environments, blood eosinophils, serum total IgE, pulmonary function test, and bronchial provocation tests were obtained. Using multiple regression analysis, we evaluated factors for later asthma symptoms during a follow-up period of 4 years. @*Results@#The independent risk factors for later asthma symptoms among children with allergic rhinitis were higher body mass index (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.06–1.56; P= 0.012), a parental diagnosis of asthma (aOR, 6.19; 95% CI, 1.59–24.06; P= 0.008), residence in the rural area (aOR, 5.37; 95% CI, 1.34–21.42; P= 0.017), and a history of bronchiolitis in the first 2 years (aOR, 5.82; 95% CI, 1.42–23.80; P= 0.014). However, pulmonary functions, the levels of bronchial hyper-responsiveness, and the patterns of sensitization showed not significant factors. Children whose allergic rhinitis was treated in the follow-up period were less likely to have asthma symptoms later (aOR, 0.30; 95% CI, 0.10–0.93; P= 0.036). @*Conclusion@#In the school-aged children with allergic rhinitis, body mass index and asthma-related risk factors are crucial for developing asthma symptoms. The appropriate treatment of rhinitis may decrease asthma symptoms.

Indoor pet ownership in infancy is a risk factor for the development of sensitization to pets and asthma in childhood

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.

Cesarean section does not increase the prevalence of allergic disease within 3 years of age in the offsprings

OBJECTIVE: In this study, we evaluated the prevalence of allergic disease in offsprings delivered via the delivery modes of vaginal delivery vs. planned Cesarean section vs. Cesarean section with labor. METHODS: This study included 175 mother-neonate pairs from Severance Hospital who were enrolled in the Cohort for Childhood Origin of Asthma and allergic diseases study. Information regarding prenatal environmental factors, delivery, and diagnosis of allergic diseases was obtained from a questionnaire and medical record review. Patients with at least 3 years of follow-up data were included in this study. Results were adjusted for sex, birth weight, gestational age at birth, season of birth, neonatal intensive care unit admission, parity, breastfeeding, and maternal factors. RESULTS: A total of 175 offsprings were eligible for analysis. Among the subjects, 52.0% were delivered by vaginal delivery, 34.3% by planned Cesarean section, and 16.6% by Cesarean section with labor. Fifty-nine offsprings (33.7%) were diagnosed with allergic disease at a median age of 1 year (range 0.5–3 years). The prevalence of allergic disease was not associated with delivery mode after adjusting for confounding variables. Time period from membrane rupture to delivery, duration of the active phase, and the beginning of the pelvic division prior to Cesarean section were not associated with allergic disease development in offsprings. CONCLUSION: Cesarean section, irrespective of the occurrence of labor before surgery, did not increase the prevalence of allergic disease in infants up to 3 years of age.

Psychological Responses among Humidifier Disinfectant Disaster Victims and Their Families

To substantiate psychological symptoms following humidifier disinfectant (HD) disasters, counseling records of 26 victims and 92 family members of victims (45 were bereaved) were analyzed retrospectively. Among the victims, 34.6% had Clinical Global Impression-Severity scores of over 4, which meant they were moderately ill. While anxiety/fear and depression with respiratory symptoms were frequently observed in victims and family members, chronic psychological distress such as alcohol/smoking abuse and insomnia was relatively high in bereaved family members. In conclusion, it is important to provide mental health support for victims and their families, focusing on the characteristic symptoms of each group as well as monetary compensation.

Phenotypes of allergic diseases in children and their application in clinical situations / 소아과

Allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis, are common heterogeneous diseases that encompass diverse phenotypes and different pathogeneses. Phenotype studies of allergic diseases can facilitate the identification of risk factors and their underlying pathophysiology, resulting in the application of more effective treatment, selection of better treatment responses, and prediction of prognosis for each phenotype. In the early phase of phenotype studies in allergic diseases, artificial classifications were usually performed based on clinical features, such as triggering factors or the presence of atopy, which can result in the biased classification of phenotypes and limit the characterization of heterogeneous allergic diseases. Subsequent phenotype studies have suggested more diverse phenotypes for each allergic disease using relatively unbiased statistical methods, such as cluster analysis or latent class analysis. The classifications of phenotypes in allergic diseases may overlap or be unstable over time due to their complex interactions with genetic and encountered environmental factors during the illness, which may affect the disease course and pathophysiology. In this review, diverse phenotype classifications of allergic diseases, including atopic dermatitis, asthma, and wheezing in children, allergic rhinitis, and atopy, are described. The review also discusses the applications of the results obtained from phenotype studies performed in other countries to Korean children. Consideration of changes in the characteristics of each phenotype over time in an individual’s lifespan is needed in future studies.

Protease-Activated Receptors 2-Antagonist Suppresses Asthma by Inhibiting Reactive Oxygen Species-Thymic Stromal Lymphopoietin Inflammation and Epithelial Tight Junction Degradation

PURPOSE: Protease-activated receptor 2 (PAR2) reportedly triggers the immune response in allergic asthma. We aimed to investigate the mechanism on allergic inflammation mediated by PAR2. METHODS: Human lung epithelial cells (A549 cells) were used for in vitro, and the German cockroach extract (GCE)-induced mouse model was developed for in vivo studies. RESULTS: In A549 cells, the levels of reactive oxygen species (ROS) and thymic stromal lymphopoietin (TSLP) were significantly increased by GCE treatment, but were suppressed by PAR2-antagonist (PAR2-ant) or N-acetylcysteine (NAC) treatment. Claudin-1 was degraded by GCE, and was restored by PAR2-ant or NAC in the cells. In the mouse model, the clinical appearance including bronchial hyperresponsiveness, bronchoalveolar lavage fluid analysis and total immunoglobulin E were significantly suppressed by PAR2-ant or NAC. Moreover, TSLP levels in the lung were suppressed by the same treatments in the lung. Claudin-1 was also degraded by GCE, and was restored by PAR2-ant or NAC. CONCLUSIONS: ROS generation and epidermal tight junction degradation are triggered by protease, followed by the induction of TSLP in allergic asthma. Our findings could suggest that PAR2-ant or anti-oxidants could be considered for allergic diseases as preventive alternatives.

Prenatal Exposure to Lead and Chromium is Associated with IL-13 Levels in Umbilical Cord Blood and Severity of Atopic Dermatitis: COCOA Study

There have been few studies investigating the association between atopic dermatitis (AD) and prenatal exposure to heavy metals. We aimed to evaluate whether prenatal exposure to heavy metals is associated with the development or severity of AD in a birth cohort study. A total of 331 subjects were followed from birth for a median duration of 60.0 months. The presence and severity of AD were evaluated at ages 6 and 12 months, and regularly once a year thereafter. The concentrations of lead, mercury, chromium, and cadmium in umbilical cord blood were measured by inductively coupled plasma mass spectrometry. Cord blood mononuclear cells (CBMCs) were isolated and stimulated for analysis of cytokine production using ELISA. Heavy metal levels in cord blood were not associated with the development of AD until 24 months of age. However, a positive correlation was observed between the duration of AD and lead levels in cord blood (p=0.002). AD severity was also positively associated with chromium concentrations in cord blood (p=0.037), while cord blood levels of lead, mercury, and cadmium were not significantly associated with AD severity (p=0.562, p=0.054, and p=0.055, respectively). Interleukin-13 production in CBMCs was positively related with lead and chromium levels in cord blood (p=0.021 and p=0.015, respectively). Prenatal exposure to lead and chromium is associated with the persistence and severity of AD, and the immune reaction toward a Th2 polarization.

The risk of preschool asthma at 2–4 years is not associated with leukocyte telomere length at birth or at 1 year of age

BACKGROUND: Exposure to prenatal stress is associated with offspring allergic-disease development, and oxidative stress may mediate this relationship. OBJECTIVE: We aimed to evaluate whether leukocyte telomere length (LTL) shortening, a marker for exposure to oxidative stress, in early life is associated with increased risk of asthma development during the preschool period. METHODS: We assessed the follow-up clinical data of a subgroup from a birth cohort whose LTLs had been measured from cord-blood and 1-year peripheral-blood samples. We examined whether the LTLs would be associated with asthma development at the age of 2–4 years. RESULTS: The data of 84 subjects were analyzed. LTLs were measured from the cord-blood and 1-year peripheral blood of 75 and 79 subjects, respectively. Among them, 14 subjects (16.7%) developed bronchial asthma between 2–4 years old. Prenatally stressed subjects had marginally increased odds of developing asthma (p = 0.097). There was no significant difference in the odds of preschool-asthma development between the groups with shorter and longer cord-blood LTLs (odds ratio [OR], 0.651; 95% confidence interval [CI], 0.184–2.306) or in the odds between the groups with shorter and longer 1-year peripheral-blood LTLs (OR, 0.448; 95% CI, 0.135–1.483). Finally, subjects with both higher prenatal stress and shorter LTLs did not have significantly higher odds of preschool-asthma development (for cord-blood: OR, 1.242; 95% CI, 0.353–4.368; for 1-year peripheral-blood: OR, 1.451; 95% CI, 0.428–4.919). CONCLUSION: There was no significant association between early life LTLs and higher risk of bronchial-asthma development during the preschool years.

The Pathological Findings of Chloromethylisothiazolinone and Methylisothiazolinone-associated Lung Injury

No abstract available.

Leukocyte Telomere Length Reflects Prenatal Stress Exposure, But Does Not Predict Atopic Dermatitis Development at 1 Year

PURPOSE: Prenatal maternal stress affects offspring's atopic dermatitis (AD) development, which is thought to be mediated by the oxidative stress. We aimed to evaluate the difference in leukocyte telomere length (LTL), a marker for exposure to oxidative stress, according to the prenatal stress exposure and the later AD development. METHODS: From a birth cohort (the COhort for Childhood Origin of Asthma and allergic diseases) that had displayed a good epidemiologic association between the exposure to prenatal stress and AD development in the offspring, we selected 68 pairs of samples from 4 subject groups based on the level of prenatal maternal stress and later AD development. The LTL was measured from both cord blood and 1-year peripheral blood, and their LTLs were compared between subject groups. Finally, the proportion of AD development was examined in the subject groups that are reclassified based on subjects' exposure to prenatal stress and there LTL. RESULTS: Cord-blood LTL was shorter in prenatally stressed infants than in unstressed ones (P = 0.026), which difference was still significant when subjects became 1 year old (P = 0.008). LTL of cord blood, as well as one of the 1-year peripheral blood, was not different according to later AD development at 1 year (P = 0.915 and 0.174, respectively). Shorter LTL made no increase in the proportion of later AD development in either prenatally high-stressed or low-stressed groups (P = 1.000 and 0.473, respectively). CONCLUSIONS: Cord-blood LTL may reflect subjects' exposure to maternal prenatal stress. However, the LTL shortening is not a risk factor of increasing AD development until the age of 1, and a longer investigation may be necessary for validation. Currently, the results doubt the role of LTL shortening as a marker for risk assessment tool for the prenatal stress associated with AD development in the offspring.

Multicenter Adherence Study of Asthma Medication for Children in Korea

PURPOSE: Adherence is a major component of successful medical treatment. However, non-adherence remains a barrier to effective delivery of healthcare worldwide. METHODS: Twenty healthcare facilities (secondary or tertiary hospitals) belonging to the Korean Academy of Pediatric Allergy and Respiratory Diseases (KAPARD) participated. Questionnaires were given to patients currently receiving treatment in the form of inhalant useor oral intake or transdermal patch for mild to moderate asthma. RESULTS: A total of 1,838 patients responded to the questionnaire. Mean age was 5.98 ± 3.79 years (range: 0-18 years). With help from their caregivers, the percentage of patients that answered “taking as prescribed” was 38.04% for inhalant users, 50.09% for oral medication users and 67.42% for transdermal users. Transdermal patch users had significantly greater adherence compared to the other 2 groups (P < 0.001). The 34.15% of inhalant users, 70.33% of oral medication users and 93.00% of transdermal patch users felt that their medication delivery system was “Easy” or “Very easy” to use (P < 0.001). “Method of administration” was deemed to be the most difficult part of the treatment regimen to follow, and 76.7% of patients preferred once-daily administration (i.e., “Frequency of administration”). CONCLUSIONS: Asthma medication adherence in young children was found to be better in the transdermal patch group. This may be due to requiring fewer doses and easy to follow instructions. From an adherence point of view, the transdermal patch seems more useful for long-term asthma control in children compared to oral or inhaled medicine.

Dietary Factors Associated with Attention Deficit Hyperactivity Disorder (ADHD) in School-aged Children / 대한지역사회영양학회지

OBJECTIVES: An association between dietary patterns and mental health in children has been suggested in a series of studies, yet detailed analyses of dietary patterns and their effects on ADHD (attention deficit hyperactivity disorder) are limited. METHODS: We included 4569 children who had dietary intake data as part of the CHEER (Children's Health and Environmental Research) study conducted nationwide from 2005 to 2010. We assessed ADHD (Attention Deficit Hyperactivity Disorder) by the DuPaul's ADHD Rating Scales and dietary intake by a semi-quantitative food frequency questionnaire. Using intake data, we constructed five dietary patterns: “Plant foods & fish,” “Sweets,” “Meat & fish,” “Fruits & dairy products,” and “Wheat based.” RESULTS: The overall proportion of ADHD was 12.3%. Boys (17.8%) showed a higher rate of ADHD than girls (6.5%). The total intake of calories (85 kcal) and plant fat (2g) in the ADHD group was significantly higher than that of the normal group. ADHD was significantly negatively associated with dietary habits such as having breakfast and meal frequency, and positively associated with eating speed, unbalanced diet, overeating, and rice consumption. Regarding dietary patterns, the “Sweets” category was relevant to high ADHD risk (OR 1.59, 95% CI: 1.18, 2.15 for Q5 vs. Q1) in a linear relationship. An inverse, non-linear association was found between “Fruits & dairy products” and ADHD (OR 0.55, 95% CI: 0.39, 0.76 for Q4 vs. Q1). CONCLUSIONS: Our study confirms both positive and negative associations between diet and ADHD in elementary school age children. Moreover, linear or nonlinear associations between diet and ADHD draw attention to the possible threshold role of nutrients. Further studies may consider characteristics of diet in more detail to develop better intervention or management in terms of diet and health.

Outcomes of drug provocation tests in Korean children with suspected drug hypersensitivity reaction

PURPOSE: Drug provocation tests (DPT) are the gold standard for confirming the diagnosis of drug hypersensitivity reactions (DHRs). However, there are little studies of DPT in children. The purpose of this study was to evaluate DPT results and safety as diagnostic methods of DHR in Korean children. METHODS: We reviewed the medical records of 39 children under 18 years of age with a suspected DHR and performed DPT between January 2010 and May 2016 at Asan Medical Center. RESULTS: Total 110 DPT were performed in 39 children (20 boys and 19 girls) with a history of DHR. Clinical presentation of DHR included skin rash (n=7), pruritus (n=3), urticaria (n=18), angioedema (n=19), dyspnea (n=5), hoarseness (n=1), hypothermia (n=1), and anaphylaxis (n=5). The median age at the time of DPT was 9 years. Positive DPT were observed in 21 of 39 children (53.8%) and 28 of 110 cases (25.5%). Drugs causing positive reactions were acetaminophen in 50% (9 of 18), nonsteroidal anti-inflammatory drugs in 29.2% (14 of 48), cephalosporin in 9.1% (1 of 11), trimethoprim/sulfamethoxazole in 50% (1 of 2), local anesthetics in 10% (1 of 10), and others (levodropropizine and idursulfase) in 15.4% (2 of 13). There was no statistical difference between children who had positive and negative results in sex, age, personal and parental history of allergic disease, eosinophil count, or total IgE level. Children with positive DPT did not develop anaphylaxis during the DPT procedure. CONCLUSION: Drug provocation test is safe, and it can be considered in children with suspected DHRs.

Epidemiology of allergic diseases in Korean children

In order to overcome a certain disease, it is necessary to confirm the prevalence, natural course and risk factors of the disease. The Korean Academy of Pediatric Allergy and Respiratory Disease has become the mainstream and has been paying a great deal of attention to the epidemiologic research of allergic diseases in Korean children since 1995. In this review, we would like to summarize the International Study of Asthma and Allergies in Childhood epidemiology study in Korea, the cohort study for allergic diseases, and the national medical big data. New epidemiological studies are needed to clarify the relationships between allergic diseases and factors such as air pollution, climate changes, microbiome, and diet, which are likely to be new risk factors for allergic diseases. Based on these epidemiological studies, we hope to find ways to overcome pediatric allergic diseases in Korea and also to share epidemiologic techniques and manpower.