Challenges to paediatric tuberculosis care as perceived by health workers in Kano, North-western Nigeria

uberculosis (TB) remains the world's deadliest infectious disease that affects a third of the world's population and newly infected an estimated 10 million people in 2018. The number of TB infected Nigerians ranks sixth in the world and first in Africa. Kano State has the highest Nigerian TB prevalence. I aimed to identify Paediatric TB care challenges as perceived by Kano Medical and DOT health care providers. The study design was prospective, descriptive and cross sectional involving structured questionnaire interviews of 43 healthcare providers, during TB supervision visits of 10 Health facilities in Kano. Generated data was entered, validated and analysed using the STATA 13 statistical software package. The sample size was convenient, since it is the number of all the health providers working in the facilities assigned to the author for supervision under a supervision contract with KNCV in 2017. Of the 43 respondents, there were 26 males, with a M: F ratio of 1.5: 1. Those health workers aged from 30 and 40 years constituted 58% of respondents. The staff cadre of respondents comprised of Community Health Extension Workers [CHEW] (40%), doctors (30%) and nurses (3%). Up to 51% of respondents had over 10 years health worker experience and greater than 36 months Child TB DOT care provision. The most commonly identified challenges to paediatric TB care included poor health knowledge (97.7%), poor health seeking behaviour (95.4%), poverty (95.4%), the inability of children to cough up sputum 95.4%, late presentation (90.7%), contact tracing logistics (90.7 %), patient and community factors of stigma and discrimination (86%) and poor health worker paediatric TB knowledge (70%). Perceived health worker challenges to effective Paediatric TB care were the adult orientation of the TB programme and its contact tracing logistic challenges, inadequate health worker Paediatric TB knowledge, children's inability to cough up sputum, poverty, poor patient TB health knowledge, community stigma and discrimination, poor health seeking behaviour and late presentation.

The effects of cognitive effort on academic performance of learners with cochlear implants in a private mainstream school in Gauteng

This research investigated the phenomenon of learners with cochlear implants and their challenges with cognitive effort in private mainstream schools in Gauteng. Many learners with cochlear implants encounter academic and social challenges at school, despite the advanced technology. Objectives: This study aimed to explore how learners with cochlear implants experience cognitive effort and whether it impacts their academic potential. Methods: Research was conducted using a phenomenological design. Phenomenography was used as theoretical framework to perceive, interpret and understand experiences of the cochlear implant recipients. The six former learners who were recipients of cochlear implants were selected using purposive sampling. Semi structured interviews were utilised to gather information, which was analysed using thematic content analysis. Results: Five themes emerged from the analysis, namely auditory challenges, cognitive functioning, peer interactions, emotional health and concealed disability. This article only presents the first theme of cognitive functioning and highlights three subthemes related to cognitive effort. Findings show that many learners struggled with their concentration span and fatigue, as a result of their cognitive effort difficulties. Conclusion: This study demonstrated how learners with cochlear implants face challenges with cognitive effort at their mainstream schools. It indicates the need for awareness of and training on educating learners with cochlear implants to help them reach their academic potential. Contribution: This study contributes a unique focus on learners with cochlear implants in mainstream schools in South Africa. The study highlights that cognitive effort of learners with cochlear implants influenced their capabilities to multitask and retain information, despite the effort they have to put into listening. Further research should be conducted to develop interventions that could lesson cognitive effort while increasing learner productivity. The article responds to disability studies and inclusive education

Leukotriene D4 bronchial provocation test for detection of airway hyper-responsiveness in children / 南方医科大学学报

OBJECTIVE@#To explore the value of leukotriene D4 (LTD4) bronchial provocation test (BPT) in detection of airway hyper-responsiveness (AHR) in children.@*METHODS@#A total of 151 children aged 6 to 14 years, including 86 in remission of asthma and 65 with acute bronchitis, who were followed up in our respiratory clinic between November, 2017 and August, 2018. The children were randomly divided into LTD4 group (78 cases) and methacholine (MCH) group (73 cases). In LTD4 group, the 78 children underwent LTD4-BPT, including 46 with asthma and 32 children having re-examination for previous episodes of acute bronchitis; in MCH group, the 73 children underwent MCH-BPT, including 40 with asthma and 33 with acute bronchitis. MCH-BPT was also performed in the asthmatic children in the LTD4 group who had negative responses to LTD4 after an elution period. The major adverse reactions of the children to the two BPT were recorded. The diagnostic values of the two BPT were evaluated using receiver-operating characteristic (ROC) curve.@*RESULTS@#There was no significant difference in the results of basic lung function tests between LTD4 group and MCH group (>0.05). The positive rate of BPT in asthmatic children in the LTD4 group was significantly lower than that in the MCH group (26.1% 72.5%; < 0.05). The positive rate of BPT in children with previous acute bronchitis in the LTD4 group was lower than that in the MCH group (3.1% 15.2%). The positive rate of MCH-BPT in asthmatic children had negative BPT results in LTD4 group was 58.8%, and their asthma was mostly mild. The sensitivity was lower in LTD4 group than in MCH group (0.2609 0.725), but the specificity was slightly higher in LTD4 group (0.9688 vs 0.8485).The area under ROC curvein LTD4 group was lower than that in MCH group (0.635 0.787). In children with asthma in the LTD4 group, the main adverse reactions in BPT included cough (34.8%), shortness of breath (19.6%), chest tightness (15.2%), and wheezing (10.9%). The incidence of these adverse reactions was significantly lower in LTD4 group than in MCH group ( < 0.05). Serious adverse reactions occurred in neither of the two groups.@*CONCLUSIONS@#LTD4-BPT had high safety in clinical application of children and was similar to the specificity of MCH-BPT. However, it had low sensitivity, low diagnostic value, and limited application value in children's AHR detection.

Actualización de la prueba de provocación bronquial con ejercicio (PPBE) / Update of the bronchial provocation test with exercise

The bronchial challenge test with exercise aims to demonstrate the presence of exercise-induced bronchial hyperreactivity, characteristic of bronchial asthma. Its realization is well standardized, requiring special environmental conditions, preparation and submaximum effort of the patient. The response is measured by spirometry, and it is considered a positive exercise test a drop in the expired volume at the first second (FEV1) of 10%. This article describes the elements necessary to facilitate this exam, according to national and international standards and guidelines.

La prueba de provocación bronquial con ejercicio tiene como objetivo demostrar la presencia de hiperreactividad bronquial inducida por ejercicio, característica del asma bronquial. Su realización está bien estandarizada, requiriendo de condiciones ambientales especiales, preparación y esfuerzo submáximo del paciente. La respuesta se mide mediante espirometría, y se considera una prueba de provocación con ejercicio positivo, a una caída del volumen espirado al primer segundo (VEF1) del 10%. En este artículo se describen los elementos necesarios para facilitar la realización de este examen, acorde a normas y guías nacionales e internacionales.

Bronchodilator test in extreme old age: Adverse effects of short-acting beta-2 adrenergic agonists with clinical repercussion and bronchodilator response

SUMMARY OBJECTIVE: To evaluate chronological age as a limiting factor to perform the bronchodilator test, determine significant adverse effects of short-acting beta 2 agonists with clinical repercussions, and assess bronchodilator response in extreme-old-age patients who undergo the spirometry test. METHODS: This is a cross-sectional and retrospective study. The sample was extracted from the database (spirometer and respiratory questionnaire) of a pulmonary function service. Patients over 90 years old were included in the research, and we evaluated their bronchodilator response and its significant adverse effects that may have clinical repercussions related to the bronchodilator. RESULTS: A sample of 25 patients aged 92.12 ± 2.22 years (95% CI, 91.20 - 93.04), with a minimum age of 90 years and a maximum of 97 years and a predominance of females with 72% (18/25). The bronchodilator test was performed in 84% (21/25) of the patients. The bronchodilator response was evaluated in 19 of the 21 patients (90.47%) who underwent the bronchodilator test. Two tests did not meet the criteria of acceptability and reproducibility. No clinical adverse effects were observed with the bronchodilator medication (salbutamol) during or after the exam. CONCLUSIONS: Chronological age is not a limiting factor for the bronchodilator test, short-acting beta-2 agonists did not present adverse effects with significant clinical repercussion and were useful in the diagnosis and therapeutic guidance of extreme-old-age patients.

RESUMO OBJETIVOS: Avaliar se idade cronológica é um fator limitante para realizar prova broncodilatadora, determinar efeitos adversos significativos com repercussão clínica dos beta-2 agonistas de curta ação e avaliar a resposta broncodilatadora na espirometria, na velhice extrema. MÉTODOS: Estudo transversal, retrospectivo. Amostra extraída do banco de dados (espirômetro e questionário respiratório) de um serviço de função pulmonar. Incluídos na pesquisa pacientes com ≥90 anos, sendo avaliados a resposta broncodilatadora e efeitos adversos significativos com repercussão clínica ao broncodilatador. RESULTADOS: Amostra de 25 pacientes com idade de 92,12 ± 2,22 anos (IC 95%; 91,20 - 93,04), idade mínima de 90 anos e máxima de 97 anos, predominando o sexo feminino, com 72% (18/25). A prova broncodilatadora foi realizada em 84% (21/25) dos pacientes. A avaliação da resposta ao broncodilatador foi feita em 19 dos 21 pacientes (90,47%) que realizaram a prova broncodilatadora, uma vez que dois desses exames não preencheram os critérios de aceitabilidade e reprodutibilidade. A resposta broncodilatadora foi significativa em 10,52% (2/19) dos pacientes, ambos portadores de pneumopatia obstrutiva. Não foram observados efeitos adversos com repercussão clínica da medicação broncodilatadora (salbutamol) durante ou após sua realização. CONCLUSÕES: A idade cronológica não é um fator limitante para a realização da prova broncodilatadora, os beta-2 agonistas de curta ação não apresentaram efeitos adversos com repercussão clínica significativa e foram bastante úteis para auxiliar no diagnóstico e orientação terapêutica na velhice extrema.

Actualización en la prueba de provocación bronquial con metacolina en el niño / Update in the bronchial challenge test with methacholine in children

This document updates the recommendations of the bronchial challenge test with methacholine in children. It is based primarily on the recommendations contained in the guide on the technical standard of the bronchial challenge test for methacholine from the European Society of Respiratory Diseases. The main change is the recommendation to use PD20 (methacholine dose that causes a 20% drop in FEV1) instead of PC20 (methacholine concentration that causes a 20% drop in FEV1), which allows for comparable results when different devices and different protocols are used.

Este documento actualiza las recomendaciones de la prueba de provocación bronquial con metacolina en niños. Se basa fundamentalmente en las recomendaciones contenidas en la guía sobre el estándar técnico de la prueba de provocación bronquial de metacolina de la Sociedad Europea de Enfermedades Respiratorias. El principal cambio es la recomendación de utilizar la PD20 (dosis de metacolina que provoca una caída de 20% del VEF1) en vez de PC20 (concentración de metacolina que provoca una caída del 20% en el VEF1), lo cual permite tener resultados comparables cuando se usan diferentes dispositivos y diferentes protocolos.

Value of Exhaled Nitric Oxide and FEF(25–75) in Identifying Factors Associated With Chronic Cough in Allergic Rhinitis

PURPOSE: Chronic cough in allergic rhinitis (AR) patients is common with multiple etiologies including cough variant asthma (CVA), non-asthmatic eosinophilic bronchitis (NAEB), gastroesophageal reflux-related cough (GERC), and upper airway cough syndrome (UACS). Practical indicators that distinguish these categories are lacking. We aimed to explore the diagnostic value of the fraction of exhaled nitric oxide (FeNO) and forced expiratory flow at 25% and 75% of pulmonary volume (FEF(25–75)) in specifically identifying CVA and NAEB in these patients. METHODS: Consecutive AR patients with chronic cough were screened and underwent induced sputum, FeNO, nasal nitric oxide, spirometry, and methacholine bronchial provocation testing. All patients also completed gastroesophageal reflux disease questionnaires. RESULTS: Among 1,680 AR patients, 324 (19.3%) were identified with chronic cough, of whom 316 (97.5%) underwent etiology analyses. Overall, 87 (27.5%) patients had chronic cough caused by NAEB, 78 (24.7%) by CVA, 16 (5.1%) by GERC, and 81 (25.6%) by UACS. Patients with either NAEB or CVA (n = 165, in total) were further assigned to a common group designated as CVA/NAEB, because they both responded to corticosteroid therapy. Receiver operating characteristic curves of FeNO revealed obvious differences among CVA, NAEB, and CVA/NAEB (area under the curve = 0.855, 0.699, and 0.923, respectively). The cutoff values of FeNO at 43.5 and 32.5 ppb were shown to best differentiate CVA and CVA/NAEB, respectively. FEF(25–75) was significantly lower in patients with CVA than in those with other causes. A FEF(25–75) value of 74.6% showed good sensitivity and specificity for identifying patients with CVA. CONCLUSIONS: NAEB, CVA, and UACS are common causes of chronic cough in patients with AR. FeNO can first be used to discriminate patients with CVA/NAEB, then FEF(25–75) (or combined with FeNO) can further discriminate patients with CVA from those with CVA/NAEB.

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.

Alergia alimentar e a ácaros em crianças com dermatite atópica / Food and dust mite allergy in children with atopic dermatitis

Objetivo: Avaliar a incidência de alergia alimentar e a ácaros em crianças com dermatite atópica acompanhadas no ambulatório de alergia alimentar, em um hospital público de Belo Horizonte. Métodos: Foram selecionadas, prospectivamente, crianças com dermatite atópica acompanhadas no nosso serviço e que preenchiam os critérios diagnósticos de Hanifin e Lobtiz, independente da sua gravidade. Pacientes foram submetidos a teste alérgico por punctura para alimentos, D. farinae, D. pteronyssinus e B. tropicalis. Crianças com teste alérgico positivo para um ou mais alimentos foram submetidas a teste de provocação duplo-cego placebo controlado para o alimento suspeito, seguindo critérios previamente estabelecidos pela American Academy of Allergy, Asthma and Immunology (AAAAI). Resultados: Um total de 56 crianças foram avaliadas com idade média de 5 anos; 27 (48,2%) do sexo masculino, e 29 (51,8%) do sexo feminino. Teste alérgico para alimentos foi positivo em 33 pacientes (58,9%), e, destes, 8 (24,2%) tiveram o teste de provocação duplo-cego placebo controlado positivo para o alimento suspeito. A incidência de alergia alimentar na população estudada foi de 14,3%. Teste alérgico positivo para ácaros ocorreu em 30 pacientes, que corresponde a 53,6% da população estudada. Conclusão: Segundo o nosso estudo, a incidência de alergia alimentar nas crianças com dermatite atópica foi de 14,3%. Leite e ovo foram os únicos alimentos relacionados com dermatite atópica neste estudo. Teste alérgico para inalantes foi positivo para Dermatofagoide em 53,6% destes pacientes.

Objective: To evaluate the incidence of food and dust mite allergy in children with atopic dermatitis treated at a food allergy outpatient clinic at a public hospital in Belo Horizonte. Methods: We prospectively selected children with atopic dermatitis who were monitored at our service and who fulfilled the diagnostic criteria of Hanifin and Lobtiz regardless of severity. Patients underwent a skin prick test for foods, D. farinae, D. pteronyssinus, and B. tropicalis. Children who tested positive for one or more foods underwent a double-blind placebo-controlled challenge test for the suspected food, following criteria previously established by the American Academy of Allergy, Asthma and Immunology (AAAAI). Results: A total of 56 children were evaluated. Their mean age was 5 years; 27 (48.2%) were male and 29 (51.8%) were female. Food allergy test was positive in 33 patients (58.9%) and of those, 8 (24.2%) tested positive in the challenge test for the suspected food. The incidence of food allergy in the study sample was 14.3%. Thirty patients tested positive for dust mite allergy, accounting for 53.6% of the sample. Conclusion: In our study, the incidence of food allergy in children with atopic dermatitis was 14.3%. Milk and egg were the only foods related to atopic dermatitis in this study. Inhalant allergy test was positive for D. pteronyssinus in 53.6% of patients.

CRISPR: Challenges to South African biotechnology law

Genome editing using newly discovered tools such as CRISPR-Cas9 offers the potential to modify the genetic make-up of plants, non-human animals and humans in exact ways. Such genetic modification can serve the purpose of correcting gene defects, and can enhance certain characteristics. Apart from reigniting old ethical debates, genome editing also poses a particular challenge to legal practitioners, as this new technology does not always fit into existing definitional moulds, and it lacks clear legal precedent. In this article, we identify the most salient areas of concern in the South African legal context

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children

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

Methacholine bronchial provocation test in patients with asthma: serial measurements and clinical significance

BACKGROUND/AIMS: The methacholine bronchial provocation test (MBPT) is used to detect and quantify airway hyper-responsiveness (AHR). Since improvements in the severity of asthma are associated with improvements in AHR, clinical studies of asthma therapies routinely use the change of airway responsiveness as an objective outcome. The aim of this study was to assess the relationship between serial MBPT and clinical profiles in patients with asthma. METHODS: A total of 323 asthma patients were included in this study. The MBPT was performed on all patients beginning at their initial diagnosis until asthma was considered controlled based on the Global Initiative for Asthma guidelines. A responder was defined by a decrease in AHR while all other patients were considered non-responders. RESULTS: A total of 213 patients (66%) were responders, while 110 patients (34%) were non-responders. The responder group had a lower initial PC20 (provocative concentration of methacholine required to decrease the forced expiratory volume in 1 second by 20%) and longer duration compared to the non-responder group. Members of the responder group also had superior qualities of life, compared to members of the non-responder group. Whole blood cell counts were not related to differences in PC20; however, eosinophil concentration was. No differences in sex, age, body mass index, smoking history, serum immunoglobulin E, or frequency of acute exacerbation were observed between responders and non-responders. CONCLUSIONS: The initial PC20, the duration of asthma, eosinophil concentrations, and quality-of-life may be useful variables to identify improvements in AHR in asthma patients.

The KAAACI Standardization Committee Report on the procedure and application of the bronchial provocation tests

Bronchial provocation tests are of value in the evaluation of airway hyperresponsiveness. Nonspecific bronchial challenge (methacholine, mannitol, exercise, etc.) is used when the symptoms, physical examination, and measurements of pulmonary function are unremarkable in the diagnosis of asthma, when a patient is suspected of having occupational asthma or exercise-induced bronchoconstriction (EIB), and when a screening test for asthma or EIB is required for some occupational groups in whom bronchospasm would pose an unacceptable hazard. Methacholine inhalation challenge is most widely used pharmacologic challenge and highly sensitive. For appropriate interpretation of the results of methacholine provocation, it is important to perform the test with the standardized protocol and to recognize that inhalation methods significantly influence the sensitivity of the procedure. Indirect challenges (e.g., mannitol and exercise) correlate with airway inflammation and are more specific but less sensitive for asthma. Indirect provocation tests are used to confirm asthma, to differentiate asthma from other airway diseases, and to evaluate EIB.

Dyspnea Perception During Induced Bronchoconstriction Is Complicated by the Inhaled Methacholine in Children With Clinical Asthma

PURPOSE: Dyspnea is not widely utilized as an indicator of asthma provocation despite its universal presentation. We hypothesized that dyspnea severity was proportionate with the lung function decline, methacholine dose-step, and the degree of bronchial hyperresponsiveness (BHR). METHODS: We retrospectively analyzed 73 children's bronchial provocation test data with an assessment of dyspnea at every dose-step. Dyspnea severity was scored using a modified Borg (mBorg) scale. A linear mixed effect analysis was performed to evaluate the relationship between the mBorg scale, the percentage fall in the forced expiratory volume in 1 second (FEV1) (ΔFEV1%), the methacholine dose-step, and the degree of BHR (BHR grade). RESULTS: Subjects were divided into 5 BHR groups based on their last methacholine dose-steps. The mBorg scores did not differ significantly among BHR groups (P=0.596, Kruskal-Wallis test). The linear mixed effect analysis showed that ΔFEV1% was affected by the methacholine dose-step (P < 0.001) and BHR grade (P < 0.001). The mBorg score was affected by the dose-step (P < 0.001) and BHR grade (P=0.019). We developed a model to predict the mBorg score and found that it was affected by the methacholine dose-step and ΔFEV1%, elevating it by a score of 0.039 (χ² [1]=21.06, P < 0.001) and 0.327 (χ² [1]=47.45, P < 0.001), respectively. A significant interaction was observed between the methacholine dose-step and ΔFEV1% (χ² [1]=16.20, P < 0.001). CONCLUSIONS: In asthmatic children, inhaled methacholine, as well as the degree of BHR and lung function decline, may affect dyspnea perception during the bronchial provocation test. If we wish to draw meaningful information from dyspnea perception, we have to consider various complicating factors underlying it.

Accuracy of spirometry for detection of asthma: a cross-sectional study

ABSTRACT BACKGROUND: Asthma is a chronic inflammatory disease with airway hyperresponsiveness. Spirometry is the most commonly used test among asthmatic patients. Another functional test used for diagnosing asthma is the bronchial challenge test. The aim of this study was to analyze the accuracy of spirometry for detecting asthma in the general population. DESIGN AND SETTING: Cross-sectional study with data analysis to evaluate the accuracy of spirometry through calculating sensitivity, specificity and predictive values and through the kappa agreement test. METHODS: Subjects who constituted a birth cohort were enrolled at the age of 23 to 25 years. Spirometric abnormality was defined as reduced forced expiratory volume in one second, i.e. lower than 80% of the predicted value. Measurement of bronchial responsiveness was performed by means of the bronchial challenge test with methacholine. The gold-standard diagnosis of asthma was defined as the presence of bronchial hyperresponsiveness in association with respiratory symptoms. RESULTS: Asthma was detected in 200 subjects (10.4%) out of the sample of 1922 individuals. Spirometric abnormality was detected in 208 subjects (10.9%) of the sample. The specificity of spirometric abnormality for detecting asthma was 90%, sensitivity was 23%, positive predictive value was 22%, and negative predictive value was 91%. The kappa test revealed weak agreement of 0.13 (95% confidence interval, CI: 0.07-0.19) between spirometry and the diagnosis of asthma. CONCLUSION: Spirometry, as a single test, has limitations for detecting asthma in the general population.

Comparison on the profiles of a modified Borg scale and the pediatric dyspnea scale during an induced bronchoconstriction in children with clinical asthma

PURPOSE: Dyspnea is the cardinal symptom of asthma, but it is difficult to quantify clinically. Although modified Borg (mBorg) scale has been successfully used in adult, but there has been some difficulties to apply in children. Recently, Pediatric Dyspnea Scale (PDS) was adequately designed and has been widely used. The aim of this study is to compare 2 evaluating scales of dyspnea provoked by induced-bronchoconstriction in childhood asthma. METHODS: Seventy-three clinically suspected children with asthma were enrolled in this study. Each ‘fractional exhaled nitric oxide (FeNO)’ was documented. Forced expiratory volume in 1 second (FEV₁), mBorg score and PDS score were recorded during methacholine provocation test. RESULTS: Mapping using canonical plot demonstrated global similarity between 2 scales with some distinctive features. Whereas mBorg score showed more diverse categories in low level of dyspnea, PDS score did in medium level of it. A distribution of dyspnea perception score at a 20% decrease in FEV₁ relative to baseline (PS₂₀), a perception score of dyspnea at 20% fall in FEV1 of 2 scales represented similar wide, biphasic feature. Statistical relevance was verified with spearman correlation (R(s)=0.903, P<0.001) and Bland-Altman analysis. PS₂₀ of both scores and FeNO had no statistical relationship. While relationship between PS20 by mBorg score and the concentration of methacholine at 20% fall in FEV₁ (PC₂₀) was not significant (R(s)=0.224, P=0.154), that between PS₂₀ by PDS and PC₂₀ was weak positive (R(s)=0.29, P=0.063). CONCLUSION: PDS had similar pattern to assess the dyspnea with the mBorg scale suggesting adequacy of PDS in evaluating pediatric clinical asthma. We expect these scales to help clinical practice in complementary ways.

Relationship between atopy and bronchial hyperresponsiveness to indirect stimuli in asthmatic children

PURPOSE: Both atopy and bronchial hyperresponsiveness (BHR) are characteristic features of asthma. Several BHR studies comparing groups of atopic and nonatopic asthmatics have reported conflicting results. The aim of this study was to compare BHR to indirect stimuli, such as mannitol or exercise, between atopic and nonatopic asthmatics in children. METHODS: We performed a retrospective analysis of data from 110 children with asthma, aged 6–18 years using skin prick tests, and serum total and specific IgE levels. Atopy degree was measured using the sum of graded wheal size or the sum of the allergen-specific IgE. Bronchial provocation tests (BPTs) using methacholine were performed on all subjects. BPTs using indirect simuli, including exercise and mannitol, were also performed. RESULTS: Asthma cases were classified as atopic asthma (n=83) or nonatopic asthma (n=27) from skin prick or allergen-specific IgE test results. There was no significant difference in the prevalence of BHR to mannitol or exercise between atopic and nonatopic asthmatics. Atopic asthma had a significantly lower postexercise maximum decrease in % forced expiratory volume in 1 second (FEV1) (geometric mean [95% confidence interval]: 31.9 [22.9–40.9] vs. 14.0 [9.4–18.6], P=0.015) and a methacholine PC20 (provocative concentration of methacholine inducing a 20% fall in FEV1) than nonatopic asthmatics (geometric mean [95% confidence interval]: 1.24 [0.60–1.87] ng/mL vs. 4.97 [3.47–6.47]) ng/mL, P=0.001), whereas mannitol PD15 (cumulative provocative dose causing a 15% fall in FEV1) was not significantly different between the 2 groups. CONCLUSION: There was no significant difference in the prevalence of BHR to mannitol or exercise between atopic and nonatopic asthmatics in children.

Usefulness of House Dust Mite Nasal Provocation Test in Asthma

PURPOSE: We previously reported that the skin prick test was sensitive and the serum specific immunoglobulin E test was specific for predicting positive airway responses to house dust mites (HDMs) in patients with asthma. Because the nose and bronchus are one airway, the nasal provocation test would be more specific for predicting the bronchial responses to HDM than the skin test. METHODS: The allergy skin prick test and nasal and bronchial provocation tests using HDM (Dermatophagoides farinae) were performed in 41 young men (age, 19–28 years) who wanted military certification for asthma. The nasal responses to HDM was scored according to the severity of rhinorrhea, sneezing, and nose itching. RESULTS: The prevalence of a positive skin prick test to HDM did not significantly differ between patients with (n=24) and without (n=17) an early airway reaction (EAR; 79.2% vs 70.6%, P=0.534). However, the prevalence of a positive nasal test was significantly higher in the airway responders than in the others (37.5% vs 0%, P=0.005). The concordance of a positive response to the nasal test (κ=0.332, P=0.004) but not to the skin prick test (κ=0.091, P=0.529) was significant with an EAR. The diagnostic sensitivity of the nasal test (37.5%) was lower than that of the skin prick test (79.2%), but the specificity was higher (100% vs 29.4%). CONCLUSIONS: The skin prick test is more sensitive, whereas the nasal test is more specific and accurate, for predicting an EAR to HDM in patients with asthma.

Nonspecific Bronchoprovocation Test / 결핵및호흡기질환

Bronchial asthma is a disease characterized by the condition of airway hyper-responsiveness, which serves to produce narrowing of the airway secondary to airway inflammation and/or various spasm-inducing stimulus. Nonspecific bronchoprovocation testing is an important method implemented for the purpose of diagnosing asthma; this test measures the actual degree of airway hyper-responsiveness and utilizes direct and indirect bronchoprovocation testing. Direct bronchoprovocation testing using methacholine or histamine may have superior sensitivity as these substances directly stimulate the airway smooth muscle cells. On the other hand, this method also engenders the specific disadvantage of relatively low specificity. Indirect bronchoprovocation testing using mannitol, exercise, hypertonic saline, adenosine and hyperventilation serves to produce reactions in the airway smooth muscle cells by liberating mediators with stimulation of airway inflammatory cells. Therefore, this method has the advantage of high specificity and also demonstrates relatively low sensitivity. Direct and indirect testing both call for very precise descriptions of very specific measurement conditions. In addition, it has become evident that challenge testing utilizing each of the various bronchoconstrictor stimuli requires distinct and specific protocols. It is therefore important that the clinician understand the mechanism by which the most commonly used bronchoprovocation testing works. It is important that the clinician understand the mechanism of action in the testing, whether direct stimuli (methacholine) or indirect stimuli (mannitol, exercise) is implemented, when the testing is performed and the results interpreted.