Anaphylaxis in children: Effect of age and atopic status.

BACKGROUND: Anaphylaxis is a life-threatening allergic reaction with rising incidence worldwide. Young children's limited ability to express symptoms adds unique diagnostic challenges. OBJECTIVE: To study on anaphylaxis in children, including triggers, symptoms, treatment, atopic status impact, and adrenaline injection time intervals. METHODS: In-patient medical records of children who were diagnosed with anaphylaxis during 2014-2021 were reviewed. RESULTS: One hundred thirty-three anaphylaxis events were identified. Food (47%) was the most common trigger, followed by drugs (31%), blood components (17%), insects (3%), and idiopathic causes (2%). Ten cases of refractory anaphylaxis, 2 cases of biphasic reactions, and 1 case of persistent anaphylaxis were found. There were no reported fatalities. The most common presentations involved the skin (94%), followed by the respiratory (73%), gastrointestinal (47%), and cardiovascular (42%) systems. In atopic patients, wheezing was more prominent than in those without atopy (p-value = 0.017). In the non-atopic patients, there was a higher incidence of cardiovascular symptoms, particularly hypotension (p-value = 0.001), compared to individuals with atopy. Children under 5 years old with mild-moderate anaphylaxis required more time to reach the hospital (147.0 vs. 45.0 minutes, p = 0.033) and to receive adrenaline injections (35.0 vs. 9.0 minutes, p-value = 0.017) than those with severe anaphylaxis. CONCLUSION: Childhood anaphylaxis is prevalent. Children with mild-moderate anaphylaxis experienced delays in hospital visits and adrenaline administration. Education on allergies is needed to improve the identification and prompt response to anaphylactic reactions, especially in young children.

Allergic rhinitis in remission with house dust mite subcutaneous immunotherapy.

BACKGROUND: House dust mite subcutaneous immunotherapy (HDM SCIT) is a therapeutic option for allergic rhinitis (AR) patients who are unable to properly manage symptoms with standard medications. OBJECTIVE: This study aimed to determine long-term efficacy and identify predictive factors in the clinical remission of AR patients who completed and discontinued HDM SCIT. METHODS: This study included 240 AR patients, who completed a three-year course of HDM SCIT at two tertiary hospitals and were currently being discontinued. We followed-up the patients to ask about their current symptoms and allergy medication. Clinical remission was defined by patients who no longer required daily intranasal steroid or oral antihistamine. We compared patients in clinical remission to those still taking medication. RESULTS: The enrolled patients had a median age of 21.0 (11.0-36.0) years at the time they began HDM SCIT. The clinical remission of AR was achieved in 174 (72.5%) patients. Starting HDM SCIT before the age of 15 and not having asthma were identified as significant and independent predictors of remission (aOR 4.44; 95%CI, 1.72-11.50; p-value 0.002, and 2.67, 95%CI 1.00-7.12; p-value 0.049), respectively, as determined by multivariate logistic regression analysis. There were no significant differences in HDM SCIT duration or sensitization patterns between patients in remission and those on medication after discontinuing HDM SCIT for at least one year. CONCLUSION: HDM SCIT exhibited persistent long-term efficacy after treatment discontinuation. Starting HDM SCIT before the age of 15 and without asthma comorbidity might be predictors of AR remission with HDM SCIT.

Characterization of gut microbiome profile in children with confirmed wheat allergy.

BACKGROUND: Food allergies pose serious health risks, including life-threatening anaphylactic reactions, increased morbidity, and reduced quality of life. Wheat allergy is a common concern in Asia. There is growing interest in understanding the potential association between dysregulation of the gut microbiome and the development of food allergies. OBJECTIVE: This study aimed to explore the gut microbiome of Thai children with wheat allergy and its potential association with allergic responses. METHODS: Microbial abundance was assessed using Quantitative Insights into Microbial Ecology 2 (QIIME2) microbiome analysis based on 16S rDNA data. The correlation between microbial richness and relevant parameters was evaluated using the Spearman correlation analysis. Additionally, the microbial community functions were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2). RESULTS: The gut microbiome analysis revealed significant differences between the two groups at the phylum and genus levels. Firmicutes (p = 0.012) and Verrucomicrobia (p < 0.001) were enriched in wheat-allergic children, whereas specific gut microbes such as Megamonas (p = 0.04), Romboutsia (p < 0.001), Fusobacterium (p < 0.001), Clostridium senso stricto1 (p < 0.001), and Turicibacter (p < 0.001) were more abundant in healthy children. Anaerostripes (p = 0.011), Erysipelatoclostridium (p < 0.001), Prevotella 2 (p < 0.001), Ruminiclostridium 5 (p < 0.001), and Clostridium innnocuum (p < 0.001) were enriched in children with a confirmed wheat allergy. Functional analysis indicated disparities in the pathways related to arginine and polyamine biosynthesis. CONCLUSION: These findings offer valuable insights into the gut microbiome of children with wheat allergy and its potential impact on symptom severity, laying the groundwork for further research and interventions aimed at addressing this health concern.

A real-world data analysis of distribution and inconsistency between total serum IgE and allergen-specific IgE results in clinical practice.

BACKGROUND: The inconsistency between serum total IgE (tIgE) and allergen-specific IgE (sIgE) results is often encountered in clinical practice, but the distribution and influencing factors of the inconsistent results have not been fully understood. OBJECTIVE: The aim of this study was to analyze the distribution and inconsistency between tIgE and sIgE test results. METHODS: A retrospective study, from the electronic medical records of 2139 patients who underwent both tIgE and sIgE tests, from January to December 2023 was reviewed. The tIgE and sIgE results and their distribution, as well as their inconsistency, were analyzed based on sex, age, and disease subgroups. RESULTS: 36.2% of the patients had a positive sIgE, and 43.7% had an elevated tIgE level. sIgE and tIgE results were discordant in nearly 30% of patients, with no difference between genders, while individuals aged over 60 exhibited a significantly higher inconsistency rate than the other age groups, and the inconsistency rate between tIgE and sIgE results was significantly different among different tIgE levels, sIgE grades, positive allergen count and positive allergen types. In addition, patients with chronic urticaria (CU) had a higher inconsistency rate than those with other allergic diseases, but the difference was not statistically significant. CONCLUSION: The overall inconsistency rate between tIgE and sIgE results was about 30%. The elderly group older than 60 years old is more likely to have inconsistent results, and tIgE level, sIgE level, the number and type of positive allergens also affected the consistency of tIgE and sIgE results.

Effect of dyslipidemia, obesity, and atopic status on exhaled and alveolar nitric oxide in asthmatic children.

BACKGROUND: Dyslipidemia and obesity contribute to a pro-inflammatory state. Eosinophilic airway inflammation can be indirectly measured by fractional exhaled nitric oxide (FeNO) produced in the airways of asthmatic subjects. OBJECTIVE: To compare exhaled nitric oxide (NO) and alveolar NO in asthmatic children with and without dyslipidemia. METHODS: Asthmatic children (5-18 years old) had fasting serum low-density lipoprotein cholesterol, triglyceride, and high-density lipoprotein cholesterol (HDL-C) concentrations, and C-reactive protein (CRP) concentrations measured. FeNO was measured at constant flow rates of 20, 50, 100, and 300 ml/s by the chemiluminescence method. NO concentrations in tissue of the upper airways (CawNO) and the total flux of NO in the conducting airways (JawNO) were determined through FeNO at 20, 100, and 300 ml/s using a mathematical model. The atopic status was assessed using the skin prick test for aero-allergens. RESULTS: One hundred forty-one asthmatic children were enrolled with a mean (standard deviation) age of 11.82 (3.38) years. Sixty-four (45.4%) children had dyslipidemia and 20 (14.2%) were obese. Children with low HDL-C concentrations had significantly higher CawNO and JawNO than those with normal HDL-C concentrations (both p = 0.03). Asthmatic children with obesity had higher CRP concentrations than those with a normal weight (p < 0.001). Atopic children had a significantly higher FeNO, CawNO, and JawNO than non-atopic children (all p < 0.05). CONCLUSIONS: This study suggests an effect of HDL-C on CawNO and JawNO in asthmatic children. An intervention that normalizes HDL-C concentrations may be beneficial for airway inflammation in asthmatic children.

Benefits of mobile messenger application in caregivers of food allergy children.

BACKGROUND: Unintentional exposure is common in children with food allergies. OBJECTIVE: To assess the benefits of newly developed food allergy application. METHODS: Caregivers of children with confirmed immediate reactions to food were enrolled to use the "Kinchew" application for one month. Kinchew provides the detail of food allergens after typing the name of specific food in the chat box. Then, the app provides the product image and detail of food allergens. Kinchew also has a menu for recording food diaries and videos on managing food allergies. Kinchew users were asked to assess their confidence in dealing with food allergies assessed by the questionnaire using 5 points Likert scale. The number of patients who experienced allergic reactions from unintentional food exposure was recorded after using Kinchew. RESULTS: Seventy caregivers were enrolled. Wheat was the most common causative food in 67% of the participants. All participants used Kinchew with a total use of 1,754 times, classified as food items searching 1080 times (62%), and recorded their food diary 674 times (38%). The number of patients who experienced allergic reactions from unintentional exposure significantly decreased from 61 (87%) to 31 (44%), p < 0.001.The user's confidence in choosing food improved significantly compared to the baseline score. In the subgroup analysis of the type of causative food, a significant improvement in confidence in food choosing was demonstrated in wheat and multiple food allergy groups. CONCLUSIONS: Well-designed food allergy mobile applications could improve caregivers' confidence in dealing with food allergies and reduce unintentional food exposure.

Skin prick test and serum specific IgE in predicting dust mite-induced allergic rhinitis diagnosed from nasal provocation test in chronic rhinitis children.

BACKGROUND: Allergen skin prick test (SPT) and serum specific immunoglobulin E (sIgE) are effective diagnostic tests in allergic rhinitis (AR), however, positive results may not always correlate with clinical allergies. A nasal provocation test (NPT) can identify the causative allergen for immunotherapy, but it's not routinely performed. OBJECTIVE: To establish the cutoff value for the house dust mite (HDM) SPT mean wheal diameter (MWD) and HDM sIgE level for identifying children with HDM-induced AR diagnosed from NPT. METHODS: Children aged 5 to 18 years old with chronic rhinitis were evaluated by HDM SPT, sIgE, and NPT. Children with positive NPT results indicated HDM-induced AR. The cutoff values of the HDM SPT and sIgE level for predicting positive NPT were determined using a receiver operating characteristic curve. RESULTS: A total of 245 children with a mean age of 9.53 ± 3 years were enrolled. HDM SPT results were positive (≥ 3 mm) in 160 (65.3%) children. HDM NPT results were positive in 176 (71.8%) children. Among children with positive HDM SPT (n = 160), 153 children (95.6%) were confirmed as having AR on NPT findings. The cutoff values for positive NPT responses were 6.6 mm for HDM SPT (yielding 100% specificity and 100% positive predictive value) and 17.0 kUA/L for sIgE (98.6% specificity and 99.2% positive predictive value). CONCLUSIONS: This study proposes HDM SPT and sIgE cutoff values for use in the diagnosis of HDM-induced AR based on NPT. These cutoff values can be used to identify HDM-induced AR children who might benefit from immunotherapy.

Regulatory T cell and cytokine changes in children undergoing 3 days rush venom immunotherapy.

BACKGROUND: Rush venom immunotherapy (VIT) is the recommended treatment for patients with Hymenoptera anaphylaxis. Specific data regarding regulatory T cell and cytokine changes in children receiving rush VIT are sparse. OBJECTIVE: To study the changing of CD4+CD25+FOXP3+ regulatory T cells (Treg) and serum cytokines in children undergoing 3 days rush VIT. METHODS: Children younger than 15 years with systemic reaction to Hymenoptera who had evidence of IgE sensitization to Hymenoptera were enrolled for 3 days rush VIT. Peripheral blood CD4+CD25+FOXP3+ Treg and serum IL-4, IL5, IL-13, IFN-γ, and IL-10 were measured at baseline before rush VIT, achieving maintenance dose, 6 months, and 12 months after reaching maintenance dose. Specific IgE to Hymenoptera was measured at baseline and 12 months after VIT. RESULTS: A total of 15 children (11 boys and 4 girls) aged 6-15 years (mean age, 10 years) were enrolled. Four children were allergic to bee and 11 children were allergic to Vespid. The levels of CD4+CD25+FOXP3+ Treg were significantly increased at 6 months after maintenance dose compared with baseline (6.58% VS 4.01%, p = 0.001). Serum IL-13, IFN-γ, and IL-10 levels did not change significantly from baseline. However, there was a significant reduction of IL-4 in the serum at 12 months after MN when compared to the baseline levels. The systemic reaction requiring epinephrine intramuscular injection occurred only in 1 case who was on Vespid venoms rush VIT. CONCLUSIONS: Three days rush VIT provide acceptable systemic reaction and able to increase the number of CD4+CD25+FOXP3+ Treg in children.

Serum Periostin Predicts Wheezing Exacerbation: A Prospective Study in Preschool Children with Recurrent Wheezing.

INTRODUCTION: Wheezing is a common problem in preschool children. Currently, there are no reliable biomarkers that can predict subsequent wheezing in preschool children. This study aimed to compare serum periostin levels between preschool children with and without recurrent wheezing and investigate its utility for predicting acute wheezing exacerbation. METHODS: Children aged 2-5 years with recurrent wheezing and healthy control children were enrolled. They were evaluated for serum periostin level at enrollment and subsequently followed for wheezing episodes in a 1-year prospective study. RESULTS: A total of 122 children were enrolled. Children in the recurrent wheezing group (n = 80) had a greater median serum periostin level (1,122.32 pg/mL [<10-6,978.93]) than that of the healthy control group (n = 40) (<10 pg/mL [<10-2,116.69]), p value = 0.006. After 1-year follow-up, subjects who experienced subsequent wheezing exacerbation episodes had a greater median of periostin level (5,321 pg/mL) compared with those with no exacerbation (<10 pg/mL), p value = 0.014. ROC curve analysis revealed that the level of serum periostin >1,200 pg/mL, corresponding to 78.9% sensitivity and 64.6% specificity, with an AUC of 0.701, p value = 0.009, could be a predictor for acute wheezing exacerbation within 1 year. Besides, subjects with serum periostin >1,200 pg/mL had greater odds of subsequent wheezing episodes compared with those with lower levels of serum periostin (adjusted odds ratio 10.0, 95% confidence interval: 2.3-43.5). CONCLUSIONS: Preschool children with recurrent wheezing have a greater serum periostin level than healthy control. Serum periostin may be a valuable biomarker for predicting acute wheezing exacerbations in the following year.

Report of clinical presentations and two novel mutations in patients with Wiskott-Aldrich syndrome/X-linked Thrombocytopenia.

Wiskott-Aldrich syndrome (WAS)/X-linked thrombocytopenia (XLT) is a rare X-linked disease characterized by thrombocytopenia, eczema, and recurrent infection. In addition, WAS/XLT increases incidence of autoimmune diseases and malignancies. We reported 7 male patients, 2 with WAS and 5 with XLT, from 6 different families. Two novel mutations, p.Gly387GlufsTer58 and p.Ala134Asp, were identified in patients with WAS. Both patients had severe clinical phenotypes compatible with classic WAS and developed lethal outcomes with intracranial hemorrhage. Other than that, one patient with XLT developed pineoblastoma.

Association of Dyslipidemia and Respiratory Resistance Assessed by the Forced Oscillation Technique in Asthmatic Children.

PURPOSE: This study aimed to evaluate the associations between dyslipidemia and pulmonary function parameters assessed by spirometry and the forced oscillation technique in asthmatic children. METHODS: Asthmatic children (5-18 years old) had fasting serum lipid profiles including low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) concentrations, and C-reactive protein (CRP) measured. Pulmonary function tests were assessed by spirometry and the forced oscillation technique (FOT). RESULTS: One hundred forty-one asthmatic children were enrolled with a mean (SD) age of 11.82 (3.38) years. Eighty-eight (62.4%) children were boys, 64 (45.4%) had dyslipidemia, and 20 (14.2%) were obese. Among the children with dyslipidemia, a high LDL-C concentration (65.6%) was the most common form of dyslipidemia, followed by high TC (57.8%), high TG (35.9%), and low HDL-C concentrations (15.6%). Multivariable analysis showed significant associations between HDL-C concentrations and respiratory resistance at 5 Hz (R5) and respiratory resistance at 20 Hz (R20), and TC concentrations were modestly associated with reactance at 5 Hz (X5), the frequency of resonance (Fres), and the area of reactance (ALX). Asthmatic children who had high LDL-C concentrations had a significantly higher expiratory phase R5, whole breath R20, and expiratory phase R20 than those in children with normal LDL-C concentrations. CONCLUSION: This study suggests an association of blood cholesterol, especially HDL-C and LDL-C, and respiratory resistance measured by the FOT, irrespective of the obesity status. An intervention for improving LDL-C and HDL-C concentrations may be beneficial on lung function parameters in asthmatic children. CLINICAL TRIAL REGISTRATION: TCTR20200305005; date of registration: 03-04-2020 (retrospectively registered).

Zinc and vitamin C deficiencies associate with poor pulmonary function in children with persistent asthma.

BACKGROUND: One of the pathophysiologic mechanisms involved in asthma is the increase in oxidative stress. Zinc (Zn), vitamin C (VC), and vitamin E (VE) have antioxidant functions. However, the status of oxidative stress, Zn, VC, and VE in Thai asthmatic children have not been reported. OBJECTIVE: We aimed to evaluate the status of oxidative stress, Zn, VC, VE, pulmonary function tests, and airway inflammation in Thai asthmatic children with persistent asthma. METHODS: In this cross-sectional study, the data was collected from asthmatic children aged 7-17 years. The plasma PGF2α concentration as a marker of oxidative stress was measured using an ELISA kit. Plasma Zn concentration was measured through atomic absorption spectrophotometry. Plasma VC and VE concentrations were determined using HPLC. Pulmonary function tests were evaluated as forced expiratory volume in first second (FEV1) and forced vital capacity (FVC), using a spirometer. The status of airway inflammation was determined by measuring fractional exhaled nitric oxide. RESULTS: There were 76 asthmatic children in this study. Seventy-two participants had high oxidative stress. All participants had Zn deficiency. Nearly 40% of participants had VC deficiency. VC deficiency was associated with severe asthma and airway obstruction. Plasma Zn concentrations were positively correlated with FEV1 (r = 0.27) and FEV1/FVC ratio (r = 0.65). CONCLUSIONS: Deficiency of Zn and/or VC was related to severe asthma and decreased pulmonary function. Nutrition assessment and management should be considered to alleviate asthma burden.

Successful haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide in a child with X-linked chronic granulomatous disease: A first report in Asia.

BACKGROUND: HLA-matched hematopoietic stem cell transplantation (HSCT) is the curative treatment for chronic granulomatous disease (CGD). OBJECTIVE: To report a case of X-linked CGD with active infection successfully treated by haploidentical HSCT with post-transplant high dose cyclophosphamide (PTCY). METHODS: A 5-year-old Thai boy with CGD was undergone for haploidentical HSCT using PTCY with correction of the phagocytic function. He presented with Chromobacterium violaceum liver abscess at the age of 9 months and experienced recurrent perianal abscess and invasive pulmonary aspergillosis even receiving antimicrobial prophylaxis. PTCY was given on day 3 and 4, after CD34+ cells infusion. RESULTS: The peripheral blood-nucleated cell chimerism showed 100% on day 16 and remained 100%. Dihydrorhodamine (DHR) assay on day 108 and day 214 showed normal results. Currently at 22 months post HSCT, he does not receive antibiotic and anti-fungal prophylaxis. CONCLUSIONS: Haploidentical HSCT with PTCY could be an effective treatment option for children with CGD.

Effect of vitamin D on lung function assessed by forced oscillation technique in asthmatic children with vitamin D deficiency: A randomized double-blind placebo-controlled trial.

BACKGROUND: The role of vitamin D and asthma in pulmonary function changes showed conflicting result. OBJECTIVE: To evaluate if vitamin D treatment would improve lung function assessed by forced oscillation technique (FOT) in vitamin D deficient asthmatic children. METHODS: A randomized double-blind placebo-controlled trial was performed in children, aged 3-18 years with well controlled asthma. Serum total 25(OH)D and FOT parameters including respiratory resistance at 5 Hz (R5), at 20 Hz (R20), respiratory reactance at 5 Hz (X5) and area of reactance (ALX), resonance frequency (Fres) were evaluated at baseline, 1 month and 3 months. Vitamin D deficient patients (serum total 25(OH)D < 20 ng/ml) were randomized to receive treatment with vitamin D2 (tVDD) or placebo (pVDD). Non-vitamin D deficient patients (nVDD) received placebo as a control group. RESULTS: A total of 84 children were recruited, 43 patients in nVDD group, 20 in tVDD group and 21 in pVDD group. There were no significant differences in age, sex, height and weight among groups. There were no significant differences of FOT parameters among groups at all visits. There was a trend toward decrease in R5/R20 from baseline to 1 month and 3 months visit in all groups, but the statistically significant improvement was observed only in nVDD group. Serum 25(OH)D showed no correlation with % predicted of FOT measures. CONCLUSIONS: Vitamin D treatment in asthmatic children who had vitamin D deficiency may have no short term beneficial effect on pulmonary function assessed by FOT. Vitamin D supplementation in all asthmatic patient needs further study.

Efficacy of a newly developed cartoon video on dry powder inhaler technique: a multicenter study.

BACKGROUND: One of the factors associated with uncontrolled pediatric asthma is inadequate delivery of inhaled medication to the lungs. Incorrect inhaler technique has been reported. We developed a 2-minute cartoon video instruction aiming to improve dry powder inhaler (DPI) technique. OBJECTIVE: To assess the efficacy of video instruction in improvement of DPI technique in Thai children with asthma. METHODS: The prospective multicenter cohort study was conducted during March 2018 - February 2019. Children with asthma aged 6-15 years were recruited from the outpatient departments. Five videotapes demonstrated how the patients use DPI devices were recorded as the followings: before and after watching video (V1pre and V1post), at one-month (V2post), at three-month (V3post) after watching the video and at 5-month follow-up without watching the video (V4pre). Scoring of correct DPI steps were evaluated by two independent respiratory specialists. RESULTS: Of 57 patients recruited, 30 used Accuhaler™ while 27 used Easyhaler™. In Accuhaler™ group, the median age (range) of 10 (8, 11) year. The mean score of V1pre, V1post, V2post and V3post were 10.7, 12.3, 12.4, and 12.2 out of 14 respectively. In Easyhaler™ group, the median age (range) of 11 (9-12) year. The mean score of V1pre, V1post, V2post and V3post were 8.6, 10.4, 11.2 and 11.4 out of 12 respectively. At the five-month follow-up, without watching video, the V4pre score was still as high as 12.9 ± 1.3 in Accuhaler™ and 11.8 ± 0.4 in Easyhaler™. CONCLUSIONS: Our video instruction could improve Accuhaler± and Easyhaler± technique among Thai children with asthma.

Reference value of Forced Oscillation Technique for healthy preschool children.

BACKGROUND: The reference values of Forced Oscillation Technique (FOT) parameters of the inspiratory and expiratory phase for preschool children have not yet been established. OBJECTIVE: To evaluate FOT measures in Thai healthy preschool children. METHODS: Preschool children, aged 3-6 years, were screened. Children who were positive for the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire for asthma, positive family history of allergic diseases, recent lower respiratory tract infections, and environmental tobacco smoke were excluded. FOT parameters, including resistance (Rrs), reactance (Xrs), frequency of resonance (Fres) and area of reactance (ALX), were measured. RESULTS: A total of 390 healthy children with the mean age of 5.1 ± 0.9 years were enrolled. FOT was successfully performed in 378 children (96.9%). The mean (SD) for the whole breath (WB) resistance at 5Hz (R5), 20 Hz (R20) and R5-20 were 11.49 (2.69) cmH2O/L/s, 9.46 (2.19) cmH2O/L/s and 2.02 (0.82) cmH2O/L/s, respectively. The median (IQR) for WB reactance at 5Hx (X5), Fres and ALX were -1.51 (-2.37 to -0.96) cmH2O/L/s, 11.17 (8.50-15.65) Hz, and 7.53 (3.72-14.32) cmH2O/L/s, respectively. Significantly difference in WB R5, R20, X5, Fres and ALX between male and female children were demonstrated. The expiratory phase R5, R20, R5-20 were significantly higher than those of the inspiratory phase (p < 0.001). There are significant correlations between the height and FOT parameters. Reference curve for the FOT parameters was generated based on height using the lambda-mu-sigma (LMS) method. CONCLUSIONS: Reference curve of FOT parameters measured in healthy preschool children were demonstrated. Majority of preschool children could perform FOT method.

Association of HLA genotypes with Beta-lactam antibiotic hypersensitivity in children.

BACKGROUND: Beta-lactam (BL) antibiotics hypersensitivity is common in children. Clinical manifestation of BL hypersensitivity varies from mild to severe cutaneous adverse drug reactions (SCARs). OBJECTIVE: To determine the association of HLA genotype and BL hypersensitivity and the prevalence of true drug allergy in patients with history of BL hypersensitivity. METHODS: A case-control study was performed in 117 children with aged 1-18 years. Children with history of non-SCARs BL hypersensitivity were evaluated for true drug hypersensitivity including skin test and drug provocation test. Tolerant control patients were children who could tolerate BL for at least 7 days without hypersensitivity reaction. HLA genotype (HLA-A, HLA-B, HLA-C and HLA-DRB1) were performed in 24 cases and 93 tolerant controls using PCR-SSO (polymerase chain reaction - sequence specific oligonucleotide probes). RESULTS: There were association of HLA-C*04:06 (OR = 13.14, 95%CI: 1.3-137.71; p = 0.027), and HLA-C*08:01 (OR = 4.83, 95%CI: 1.93-16.70; p = 0.016) with BL hypersensitivity. HLA-B*48:01 was strongly associated with immediate reaction from BL hypersensitivity (OR = 37.4, 95%CI: 1.69-824.59; p = 0.016) while HLA-C*04:06, HLA-C*08:01 and HLA-DRB1*04:06 were associated with delayed reaction (p < 0.05). Among 71 cases who were newly evaluated for BL hypersensitivity, only 7 cases (9.8%) had true BL hypersensitivity. CONCLUSIONS: Less than 10% of children with suspected of BL hypersensitivity have true hypersensitivity. There might be a role of HLA-B, HLA-C and HLA-DRB1 genotype in predicting BL hypersensitivity in Thai children.

The effectiveness of newly developed written asthma action plan in improvement of asthma outcome in children.

BACKGROUND: Providing asthma education about controller medication use and appropriate management of asthma exacerbation are the keys to improving the disease outcome. Many asthma guidelines recommend that physicians provide written asthma action plan (WAAP) to all of their asthmatic patients. However, the benefit of WAAP is unclear. Thus, we have created a new WAAP which is simplified in Thai and more user friendly. OBJECTIVE: To determine the effectiveness of the newly developed asthma action plan in management of children with asthma. METHODS: Asthmatic children who meet inclusion criteria all received the WAAP and they were followed up for 6 months with measurement of outcome variables, such as asthma exacerbation that required emergency room visit, unscheduled OPD visit, admission and school absence in order to compare with the past 6 months before receiving the WAAP. RESULTS: The analyzed outcomes of forty-nine children show significantly reduced emergency room visit (P-value 0.005), unscheduled OPD visit (P-value 0.046), admission days (P-value 0.026) and school absence days (P-value 0.022). Well controlled group and mild severity group were not the factors that contribute to decreased emergency room visit but step up therapy may be the co-factor to decreased ER visit. CONCLUSIONS: The results of this study suggest that the provision of newly developed WAAP is useful for improving self- care of asthma patients and reducing asthma exacerbation.

Needle length for epinephrine prefilled syringes in children and adolescents: Is one inch needle appropriate?

BACKGROUND: Intramuscular epinephrine is the first line drug in the treatment of anaphylaxis. This study was to identify the appropriateness of 1 inch needle length for epinephrine prefilled syringes in children. METHODS: Children aged 1 month to 18 years were enrolled. Skin to muscle depth (STMD) and skin to bone depth (STBD) were measured using an ultrasonography at the mid-anterolateral thigh. A 1 inch needle was considered as being appropriate if the STBD was more than 1 inch and the STMD was less than 1 inch. RESULTS: Seventy five infants, 75 pre-school aged children, 75 school aged children and 147 adolescent were enrolled: 196 (52.7%) children were male. A 1 inch needle length was appropriate for 61% of the infants, for 88% of the preschool children, for 99% of the school aged children and for 95% of the adolescents. Thigh circumference ≥23 cm, BMI ≥16 kg/m2 and BW ≥ 6 kg in infants provided the sensitivity of 74%-96% in predicting the appropriateness of 1 inch needle. In preschool group, thigh circumference ≥25 cm, BMI ≥13.5 kg/m2 and BW ≥ 10 kg provided the sensitivity of 98.5-100% in predicting the appropriateness of 1 inch needle. Thigh circumference ≥ 49 cm in adolescents provided the sensitivity of 75% in predicting that a 1 inch needle was too short. CONCLUSION: One inch needle length may not be appropriated for intramuscular injection at thigh in all children. Thigh circumference, BMI and body weight are useful for predictor for using the 1 inch needle.