The prevalence of environmental exposure to perceived asthma triggers in children with mild-to-moderate asthma: data from the Childhood Asthma Management Program (CAMP)

BACKGROUND: The Childhood Asthma Management Program, a 5-year randomized clinical trial of treatments for childhood asthma, has enrolled and characterized a cohort of 1041 children with mild-to-moderate asthma. OBJECTIVE: We sought to describe self-reported sensitivities and environmental exposures and investigate the relationships between self-report of these exposures as asthma triggers and their prevalence in the home. METHODS: Self-reports of sensitivities and home exposures were obtained by interview with the child or parent. Sensitivities were further assessed by using allergy skin testing (prick or puncture) against a core battery of allergens. Home exposures were further assessed by using analysis of a home dust sample. RESULTS: Environmental exposures were surprisingly common despite self-reported sensitivities to environmental factors. Of patients reporting that cigarette smoking frequently causes asthma symptoms, 26% reported having at least one parent who smokes cigarettes. Thirty-nine percent of patients reporting that exposure to animals frequently causes asthma symptoms live with a furry pet in their home. We found a smaller proportion of homes with a high level of cat allergen (P <.001) among the children who reported that animals frequently or always trigger asthma symptoms compared with those who reported that animals never or occasionally trigger asthma symptoms, suggesting modification of the home environment. No such results were seen for dog exposure. However, clinical symptoms did not reduce exposure to parental cigarette smoking (P =.15), house dust (P =.31), or damp and musty areas (P =.51). CONCLUSION: These data suggest that children with mild-to-moderate asthma are frequently symptomatic and exposed to a wide variety of environmental exposures that are perceived to trigger symptoms by means of self-report. Although environmental modification of asthmatic homes may occur, many children remain exposed to agents that are known to trigger their asthma.     

Nocturnal awakening caused by asthma in children with mild-to-moderate asthma in the childhood asthma management program

BACKGROUND: Nocturnal symptoms of asthma are a cause of significant morbidity and are included as a central feature in the categorization of asthma severity. OBJECTIVES: Data from the Childhood Asthma Management Program were used to estimate the prevalence of nocturnal awakenings in 1041 children with mild-to-moderate asthma and to investigate the relationships between awakenings and peak flows, severity of asthma, and allergen sensitivity and exposure. METHODS: Daily diary care data were recorded during a 28-day interval in the Childhood Asthma Management Program screening process. The data on morning and evening peak flows, overall symptom codes, albuterol use for symptoms, and nocturnal awakenings for asthma symptoms were analyzed and compared with measures of personal characteristics, pulmonary function, and environmental characteristics of the patients. RESULTS: Three hundred fifty-one (33.7%) children experienced 1 or more night awakenings caused by asthma during the 28-day screening period while not taking any maintenance medications. Greater risk of night awakening was associated with more severe asthma (greater responsiveness to bronchodilator, airway reactivity to methacholine, peak flow variability, and use of albuterol for symptoms, all P <.0001) and atopy (increased IgE and allergy skin test reactivity, both P =.0002). Those with a positive skin test response to dog and a high level of dog allergen in the home had a greater risk of night awakening caused by asthma (P =.01), as did those with a positive skin test response to cat and a high level of cat allergen in the home (P =.04). Mean daily symptom code and use of albuterol for asthma symptoms increased in the 3 days immediately before a single awakening compared with in the 4 to 6 days before the awakening (P =.02 and P =.01, respectively); however, both morning and evening peak flows as a percentage of personal best were similar in both intervals. Mean daily symptom code and daily use of albuterol were greater in the 3 days after an awakening than in the 3 days before (P <.0001 and P =.0002, respectively). Mean evening peak flow percentage of personal best the day after an episode of awakening was lower when a second consecutive awakening occurred than when there was only a single awakening (P =.01). CONCLUSIONS: Nocturnal awakening occurred in one third of the children with mild-to-moderate asthma during a month of relative stability and appears to be an indicator of asthma that is becoming increasingly severe.     

MCP-1 gene regulatory region polymorphism in Chinese children with mild, moderate and near-fatal asthma

BACKGROUND: A polymorphism in the monocyte chemoattractant protein 1 (MCP-1) gene regulatory region has been associated with asthma in Caucasians. This polymorphism is possibly endemic to the Asian region, but its impact on Asian populations is unclear. In addition, the relationship of this marker with life-threatening asthma has not been clarified. The aim of this study was to test the genetic association between the MCP-1 -2518A/G polymorphism and asthma/atopy in a cohort of Chinese children, with particular emphasis on those patients who had experienced life-threatening asthma attacks. METHODS: Forty-eight children with near-fatal asthma, 134 mild-to-moderate asthmatics, 69 allergic-disorder cases without asthma, and 107 nonasthmatic, nonatopic control children were genotyped by a polymerase chain reaction-based assay. RESULTS: Comparison of the four groups of children (n = 358) revealed no detectable differences in genotype or allele frequencies of the MCP-1 -2518A/G polymorphism. There was no evidence of association between the polymorphism and any of the outcomes of interest including clinical severity, blood eosinophil count, atopy, total serum IgE levels, and degree of bronchial hyper-responsiveness. CONCLUSION: These results suggest that the MCP-1 -2518A/G polymorphism is not a risk factor for near-fatal asthma. Furthermore, this polymorphism seems to play no role in the development of asthma or atopy in Chinese subjects, possibly as a result of the genetic heterogeneity between Asian and Caucasian populations with respect to regulation of MCP-1 expression. Our results underscore the necessity of accounting for ethnic background in the investigation of asthma-predisposition genes.     

Prevalence of symptoms of childhood asthma, allergic rhinoconjunctivitis and eczema in the Pacific: the International Study of Asthma and Allergies in Childhood (ISAAC)

The International Study of Asthma and Allergies in Childhood (ISAAC) has provided valuable information regarding international prevalence patterns and potential risk factors for asthma, allergic rhinoconjunctivitis and eczema. However, the only Pacific countries that participated in ISAAC Phase I were Australia and New Zealand, and these included only a small number of Pacific children. Phase III has involved not only repeating the Phase I survey to examine time trends, but also to include centres and countries which are of interest but did not participate in Phase I. The ISAAC Phase III study was therefore conducted in the Pacific (in French Polynesia, New Caledonia, Tonga, Fiji Islands, Samoa, Cook Islands, Tokelau Islands and Niue). The overall prevalence rates of current symptoms (in the last 12 months) were 9.9% for asthma, 16.4% for allergic rhinoconjunctivitis and 10.7% for atopic eczema. The prevalence of current wheezing (9.9%) was generally much lower than that has been observed in Pacific children in New Zealand (31%), but there was considerable variation between the various Pacific centres: Tokelau Islands (19.7%), Tonga (16.2%), Niue (12.7%), French Polynesia (11.3%), Cook Islands (10.6%), Fiji Islands (10.4%), New Caledonia (8.2%) and Samoa (5.8%). The reasons for these differences in prevalence across the Pacific are unclear and require further research. The finding that prevalence levels are generally considerably lower than those in Pacific children in New Zealand adds to previous evidence that children who migrate experience an altered risk of asthma as a result of exposure to a new environment during childhood.     

The effectiveness of the long-term treatment with pranlukast in pediatric patients with mild to moderate asthma]

To investigate the efficacy of the long-term treatment with pranlukast, a specific cysteinyl leukotriene receptor antagonist, in pediatric patients with mild to moderate asthma, 77 pediatric asthmatic patients who received pranlukast for up to 36 months (mean duration, 13 months) were evaluated retrospectively. Treatment with pranlukast resulted in improvements from the pretreatment baseline in asthma attacks per month, episodes of hospitalization, and episodes of intravenous amynophiline treatment on emergent clinic visits. The percentage of responders who had marked or moderate improvements in the above-mentioned parameters of asthma control was 79%. In conclusion, pranlukast caused significant improvements in long-term asthma control in pediatric patients with mild to moderate asthma.     

Behavior problems and adaptive functioning in children with mild and severe closed head injury.

Assessed behavior problems and adaptive functioning in children with mild or severe closed head injuries, on average more than 2 years postaccident. To ensure that any problems detected in the present study were not merely preexisting problems, potential subjects were excluded if there was a history of preexisting CNS damage, significant developmental delay, or behavior problems. Children with severe head injuries had an excessive rate of behavior problems and impaired adaptive functioning. Children with mild head injuries also had an excessive rate of behavior problems (comparable to that of children with severe head injuries) but did not have impaired adaptive functioning. Results are discussed in terms of six alternative ways brain injury and behavior problems can be related functionally.     

Achieving and maintaining asthma control in an urban pediatric disease management program: the Breathmobile Program

BACKGROUND: National guidelines suggest that, with appropriate care, most patients can control their asthma. The probabilities of children achieving and maintaining control with ongoing care are unknown. OBJECTIVE: We sought to evaluate the degree to which children in a lower socioeconomic urban setting achieve and maintain control of asthma with regular participation in a disease management program that provides guideline-based care. METHODS: Interdisciplinary teams of asthma specialists use mobile clinics to offer ongoing care at schools and county clinics. A guideline-derived construct of asthma control is recorded at each visit. RESULTS: Two thousand one hundred eighty-five enrollees were eligible to evaluate the time to first achieve control, and 1591 patients were eligible to evaluate subsequent control maintenance. Depending on severity, 70% to 87% of patients with persistent asthma achieved control by visit 3, and 89% to 98% achieved control by visit 6. Subsequent control maintenance was highly variable. Thirty-nine percent of patients displayed well-controlled asthma (control at >90% of subsequent visits), whereas 13% displayed difficult-to-control asthma (<50% of subsequent visits). Patients from each baseline severity category were found in each group. Maintenance of control was influenced by physician-estimated compliance with the treatment plan, baseline severity, and the interval between clinic visits. CONCLUSIONS: Many children can achieve asthma control with regular visit intervals and guideline-based care; however, long-term control can be highly variable among patients in all severity categories. CLINICAL IMPLICATIONS: These findings highlight the need and feasibility for systematically tracking each patient's clinical response to individualize therapy and guide the use of population management strategies.     

Prevalence of asthma, rhinitis, and eczema in Northern Thai children from Chiang Mai (International Study of Asthma and Allergies in Childhood, ISAAC)

The Phase One International Study of Asthma and Allergies in Childhood (ISAAC) was developed for geographical and temporal comparisons of the prevalence and severity of asthma and allergic diseases in childhood within and between countries. In Thailand, a study was carried out in Bangkok and this is a further study undertaken in Chiang Mai. Using the ISAAC questionnaire, schoolchildren of two age groups were studied: 6-7 years old (n = 3,828) and 13-14 years old (n = 3,927). The data were entered and analyzed using the Epi-info computer program. The prevalence over the past 12 months, in 6-7 and 13-14 years olds, respectively, are as follows; wheezing, 5.5% and 12.6%; rhinitis, 18.5% and 38.3%; rash at flexural areas, 12.9% and 10.7%. The prevalence of these three conditions was found to be close to, but slightly lower than, that from Bangkok, except for eczema in older children.