Influence of a positive family history and associated allergic diseases on the natural course of asthma

The long-term outcomes of persistent childhood allergic asthma: a cross-sectional study from western Anatolia: childhood persistent asthma in western Anatolia

BACKGROUND

Prospective cohort studies have provided useful knowledge about the natural history of asthma. However, most of the studies are conducted in western countries but the course of the disease and long-term outcomes may differ between countries due to environmental and cultural factors.

OBJECTIVE

The aim of this study is to describe the long-term outcomes of childhood asthma, with data from a follow-up study of at least 10 years, in western Anatolia, Turkey.

METHODS

Fifty-two patients diagnosed with persistent allergic asthma participated in the study. The patient's demographics, findings on admission, age at onset of disease, time of diagnosis, history of other allergic conditions, history of parental asthma and allergic disorders, presence of pharmacotherapy and immunotherapy were obtained from patients' records. The factors influencing remission at the end of 10 years follow-up were evaluated.

RESULTS

A total of 20 patients (38.5%) were on remission at the end of 10 years. The type of allergen, multi-allergen sensitivity, eosinophilia and elevated serum immunoglobulin E on admission, accompanying allergic disorders and atopy in parents, and allergen immunotherapy did not affect the remission rate (p>0.05).

CONCLUSION

Childhood persistent asthma is not a homogeneous clinical entity but high clinical remission rates are obtained in western Anatolia. There is no significant predictor of clinical remission in long term follow-up. Prospective studies should be performed in larger asthmatic populations to obtain further data about the natural course of childhood asthma.

Viewpoint: the future of research in pediatric allergy: what should the focus be?

Allergic diseases have been increasing during the last three decades, and exact reasons for this are still debated. Despite intense ongoing research, a lot of aspects of allergic diseases are still poorly understood, resulting in limitations in current therapeutic approach to allergies. In this viewpoint, important unanswered research questions are raised mainly on novel therapeutic approaches to allergic children, and suggestions for future research are raised. Three aspects of pediatric allergy are distinguished: the prevention, control, and cure.

Survey of outcome of asthmatic children referred to outpatient clinic of Tabriz University of Medical Sciences

This study was designed to follow patients regarding to achieving control, identify disease exacerbations and discover relation between exacerbation and risk factors. In a cross sectional-analytic study, 400 asthmatic patients in the range of 2-14 years old who were visited at the specialized outpatient clinic of Tabriz University of Medical Sciences were divided and studied on the base of disease severity. At the end (at least one year treatment), patients were categorized based on level of disease control and one year after this stage, cases of exacerbation were identified and studied. By excluding patients with poor adherence, 342 patients continued treatment as intermittent, mild persistent, moderate persistent and severe persistent asthma (38, 235, 61 and 8 patients, respectively). After a period of one year treatment, the patients were divided as well controlled, partly controlled and uncontrolled (68, 30 and 2%, respectively). Cases of disease exacerbations were more if sinusitis, familial asthma history and poor adherence were present (p < 0.01, p < 0.001 and p < 0.05, respectively). There is meaningful association between poor adherence, sinusitis and positive family history of asthma with disease exacerbation.

Predictors of the persistence of childhood asthma

BACKGROUND

The factors relevant to the prognosis of childhood asthma differ from one population to another.

OBJECTIVES

To characterize the course of childhood asthma in the catchment area of our hospital, and to identify prognostic factors for this population.

METHODS

All children given a diagnosis of asthma in the paediatric pulmonology service of a tertiary hospital were followed up for 5 years.

RESULTS

Satisfactory control of asthma was achieved in 69 % of cases. The factors identified as associated with poor control were allergy to cats and pollen, a large number of crises in the year prior to diagnosis, and younger age at onset.

CONCLUSIONS

In our region, childhood asthma has a relatively favourable prognosis. The subsequent course of the disease appears to be determined in childhood. The persistence of symptoms appears to depend to a significant extent on the degree of atopy.

Determinants of lung function and airway hyperresponsiveness in asthmatic children

BACKGROUND

Asthma patients exhibit an increased rate of loss of lung function. Determinants to such decline are largely unknown and the modifying effect of steroid therapy is disputed. This cross-sectional study aimed to elucidate factors contributing to such decline and the possible modifying effect of steroid treatment.

METHODS

We analyzed determinants of lung function and airway hyperresponsiveness (AHR) in a Scandinavian study of 2390 subjects from 550 families. Families were selected for the presence of two or more asthmatic children as part of a genetic study, Scandinavian Asthma Genetic Study (SAGA).

RESULTS

The primary analysis studied the association between the lung function and delay of inhaled corticosteroids (ICS) after asthma diagnosis among asthmatic children and young adults with a history of regular ICS treatment (N=919). FEV(1) percent predicted (FEV(1)% pred) was 0.25% lower per year of delay from diagnosis until treatment (p=0.039). This association was significantly greater in allergy skin prick test negative children. There was no significant influence of gender, age at asthma onset, or smoking. In the secondary analysis of the whole population of 2390 asthmatics and non-asthmatics, FEV(1)% pred was inversely related to having asthmatic siblings (-7.9%; p<0.0001), asthma diagnosis (-2.7%; p=0.0007), smoking (-3.5%; p=0.0027), and positive allergy skin prick test (-0.47% per test; p=0.012), while positively related to being of female gender (1.8%; p=0.0029). Risk of AHR was higher by having asthmatic siblings (OR 2.7; p<0.0001), being of female gender (OR 2.0; p<0.0001), and having asthma (OR 2.0; p<0.0001).

CONCLUSIONS

These data suggest that lung function is lower in asthmatics with delayed introduction of ICS therapy, smoking, and positive allergy skin prick test. Lung function is lower and AHR higher in female asthmatics and subjects with asthmatic siblings or established asthma.

Are risk factors of childhood asthma predicting disease persistence in early adulthood different in the developing world?

BACKGROUND

Predictive factors of childhood asthma for favorable prognosis may differ between populations where a variety of genetic and environmental factors are present.

OBJECTIVES

To document the factors predicting disease persistence in early adulthood in Turkey.

METHODS

An outpatient cohort (n = 115) with a mean follow-up duration of 11.4 +/- 0.2 years was evaluated. Complete remission was defined as no asthma symptoms, no use of controller medication, no airflow limitation and no airway hyper-responsiveness, and clinical remission as no symptoms and no use of controller medication, within the past year.

RESULTS

The mean ages during referral and at the final visit were 5.8 +/- 0.2 and 17.1 +/- 0.2 years, respectively. Thirty-one (27%) were in complete remission, and a further 30 (26%) in clinical remission. In multivariate logistic models, diminished airflow [forced expiratory volume in 1 s (FEV1) < 80% vs > or = 80%] at the initial lung function test predicted current diminished airflow (8.422; 2.202-32.206) (odds ratio; 95% confidence interval), and presence of obstructive pattern (FEV1/forced vital capacity (FVC) < 80% vs > or = 80%) predicted current obstructive pattern (29.333; 3.022-284.724). Furthermore, female gender appeared to predict persistence of asthma symptoms (3.330; 1.250-8.333) and absence of clinical remission (2.398; 1.038-5.254); eosinophilia predicted persistence of symptoms (4.271; 1.080-16.889) and presence of airway hyper-responsiveness (3.723; 1.129-12.278).

CONCLUSIONS

Diminished airflow, female gender and eosinophilia appear to predict an adverse outcome of childhood asthma, supporting the concept that variability may exist between populations.

Methodologic aspects of the quantification of skin prick test responses: the EGEA study

BACKGROUND

The expression of responses of allergy skin prick tests is not standardized. Usual definitions of atopy are not quantitative.

OBJECTIVE

We sought to perform a biometric analysis of responses to various allergens to propose synthetic, quantitative indices independent of the heterogeneity of responses to various allergens.

METHODS

Adults (N = 1286) from the Epidemiological Study on the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA) were included in the analysis. The first step, conducted for 678 subjects with at least 1 wheal >0, was to perform a standardization of wheal diameters to obtain comparable figures for 10 allergens through use of the means of the squares of wheal size as a scaling factor. The second step was a factor analysis of the standardized responses conducted not only for all subjects but also separately for asthmatic case and nonasthmatic control subjects. Finally, the strength of the link between various dichotomous and quantitative scores was assessed with multiRAST, total IgE, and asthma. Analyzed quantitative scores were based on the number of positive responses and on the nonstandardized and standardized sizes of the wheals.

RESULTS

The standardization was efficient. Among asthmatic subjects but not other subjects, factor analysis evidenced a pattern with 3 factors, corresponding to outdoor, indoor, and mold allergens. The link study showed that all scores performed very similarly.

CONCLUSION

The number of positive tests is a quantitative score with valid biometric properties. It should be used more widely in clinical settings and in epidemiology to assess the severity of atopy.

The prognosis of bronchial asthma in childhood in Hungary: a long-term follow-up

The aim of this study was to determine the prognosis of bronchial asthma in childhood in Hungary. One hundred and forty five adults (96 men and 49 women) with a clinical history of childhood bronchial asthma were examined at the age of 28 years or above (mean age 37.6, SD 5.9 years). The patients completed questionnaires concerning their asthmatic and accompanying allergic symptoms in childhood, at the age of 18 and at present. They were all prick-tested with 12 inhalant allergens. The results showed that 42.8% of the patients had become symptom-free, but 57.2% still had intermittent or persisting asthmatic symptoms in adulthood. More patients had intermittent day-time (59%) and night-time (67%) asthmatic symptoms than persistent symptoms (41% and 33%). Accompanying allergic diseases (rhinitis, conjunctivitis, dermal and gastrointestinal diseases, and drug andfood allergies) in childhood did not definitely affect the prognosis of the bronchial asthma. The proportion of females with allergic diseases increased, and among patients with skin diseases it was significantly higher than the proportion of affected males. At the age of 18, allergic rhinitis was more frequent than in childhood. The frequencies of other allergic disorders did not change significantly. In the patients with asthmatic symptoms, molds and cat-hair allergies were more frequent than in the symptom-free group. The long-term prognosis of bronchial asthma in childhood in Hungary is relatively good, but fewer than half of the patients became symptom-free. The complaints of most of the patients were mild, but one in seven of all the adults suffered from moderate or serious bronchial asthma. Household allergens may contribute to the persistence of asthmatic symptoms.

Critical evaluation of prognostic factors in childhood asthma

Current knowledge of the natural history of asthma is improving through the establishment of a more precise definition of asthma linked with information from a number of large-scale longitudinal studies. Risk factors for the development of childhood asthma are now more clearly understood. They include gender, atopic status, genetic and familial factors, respiratory infections, and outdoor and indoor pollution (1). In the present review two types of asthma and their prognosis will be discussed: (1) Asthma in preschool children and its risk factors for evolution towards persistent childhood asthma. (2) Asthma in older children and its risk factors for evolution towards adult asthma.

Asthma from childhood to adulthood: course and outcome of lung function

Lung function (FEV1 before and after bronchodilatation) was studied prospectively over five visits in 55 asthmatic children (28 boys) from childhood to adulthood (age 30). At the last follow-up recordings were made at rest, after cold air challenge (CACh), and after bronchodilatation. Results were related to clinical asthma scoring and to sensitization to furred animals, as described in a companion paper. Lung function outcome was shown to be influenced by initial FEV1 (% predicted) and gender, but not by initial asthma severity or sensitization. FEV1 (% predicted) was higher in females than in males over the first two follow-ups, but the reverse was found over the subsequent visits. It deteriorated from childhood to adulthood in the females but improved in the males. In adulthood the females (for height 170 cm) had a steeper normalized annual fall in post-bronchodilator FEV1 than the males (55 +/- 38 vs. 25 +/- 36 ml; P = 0.006). The degree of bronchial hyperresponsiveness was associated significantly with asthma severity and the extent of sensitization to furred animals, but not with gender. The results indicate a better lung function outcome for asthmatic boys than for girls, confirming trends seen in clinical asthma severity. In adulthood the extent of sensitization to relevant perennial inhaled allergens significantly influences airway responsiveness and asthma severity, but not lung function.

Asthma from childhood to adulthood: asthma severity, allergies, sensitization, living conditions, gender influence and social consequences

The course of asthma severity, clinical allergies, allergic sensitization, changes in living conditions and social outcome were studied prospectively over five follow-up visits from the mean age of 9 to 30 years in a cohort of 28 boys and 27 girls, selected randomly among asthmatic children attending a paediatric outpatient unit. Asthma severity improved from childhood to adulthood, judged by symptom and medication scores and by the number of hospital admissions, but only nine subjects (16%) had been free from symptoms and medication over the last year of follow-up. After adolescence, asthma continued to improve among the males but not among the females. This difference could not be explained by gender differences in the course of clinical allergies or sensitization (skin-prick-tests and RAST) to common inhaled allergens, or by differences in environmental or social conditions. Sensitization to relevant perennial inhaled allergens correlated with asthma severity during adulthood. In general, clinical allergies and sensitization to inhaled allergens adopted during childhood persisted into adulthood. Approximately 10% of the subjects never adopted a clinical allergy or a positive allergy test. The social outcome was good.

Nordic consensus report on asthma management. Nordic Asthma Consensus Group

The work with the Nordic consensus report on asthma management started some years ago. The Nordic countries have common socioeconomic conditions. We acknowledge the international as well as other European guidelines providing valuable recommendations. Nevertheless, we felt the need to combine the common Nordic experiences in order to have a local statement of asthma and asthma care, based upon Nordic clinical science and tradition. The work has been rewarding and we acknowledge many valuable contributions from paediatricians, allergologists and lung physicians in all Nordic countries. The response has so far been positive and we feel that the present material reflects the main opinion of Nordic physicians taking care of asthma patients of all ages. However, the asthma and allergy research field is rapidly developing. Thus, this document should merely be regarded as a time-limited contribution to the continuing scientific discussion of this fascinating field.

Markers of impaired growth of pulmonary function in children and adolescents

Our knowledge about the age-related growth of pulmonary function is incomplete. The purpose of this study was to describe the relation of various factors to the growth of pulmonary function in children and adolescents. A population sample comprising 408 children and adolescents (7-17 yr of age at enrollment) was reexamined after a 6-yr interval. Case history was obtained by interview and questionnaire. Pulmonary function, skin prick test reactivity to common allergens, and airway responsiveness (AR) were measured using standard techniques; airway hyperresponsiveness (AHR) was defined as a concentration of histamine causing a 20% decline in FEV1 < 8 mg/ml. The cross-sectional analyses of data from the two surveys showed that the presence of asthma (p < 0.02), atopy to house dust mite (HDM) (p = 0.03), and increasing degree of AR (p < 0.002) were associated with a lower level of FEV1 %pred. The longitudinal analysis revealed that asthma (p = 0.0001) and a lower level of FEV1 (p < 0.0001) at enrollment were associated with a lower level of FEV1 at follow-up. Further, an increase in the degree of AR (p = 0. 0001), new asthma (p = 0.0002), and new atopy to HDM (p = 0.03) also predicted a lower level of FEV1 at the end of the observation period. Confining the analysis to subjects without asthma and without evidence of AHR (n = 271) showed that both persistent (p = 0.04) and new (p = 0.03) atopy to HDM predicted a lower level of FEV1 at follow-up; compared with subjects with a negative skin reaction to HDM, those subjects who were sensitized to HDM had on average a 5%pred lower level of FEV1. The growth of FEV1 in children and adolescents appears to be impaired not only by symptomatic asthma but also by an increase in the degree of AR and atopy to HDM; sensitization to HDM appears to have a negative impact on the age-related growth in FEV1 even in nonasthmatic subjects without evidence of AHR.

Evolution of asthma through childhood

The greatest incidence of childhood asthma is among males under 5 years, with decreasing numbers of new cases with age. Many young children wheeze, but remission is common especially in non-atopic children without a family history of allergy or asthma, whose wheezing relates more to infections and environmental tobacco smoke exposure. The prognosis of childhood asthma is best established from population studies, in which some two-thirds of wheezy children become symptom-free as adults, whereas follow-up studies of wheezing children seen in office or specialty clinic practice, who generally have more severe asthma, show a much greater likelihood (60-80%) of persistence of asthma into adulthood. Factors predisposing to persistence of childhood asthma include a positive family history, development of atopy, environmental exposures to allergens and cigarette smoke, markers of severity of childhood asthma, and female gender.

The natural history of respiratory symptoms in a cohort of adolescents

A cohort of 2,289 children, previously studied at the age of 6-8 yr, were followed up by means of a postal questionnaire when aged 14 -16 yr to examine the association between potential risk factors and the natural history of respiratory symptoms. Children with current symptoms, persistent symptoms, and late-onset symptoms were identified and multivariate analyses were performed to determine the independent association between risk factors and these various symptom-based subgroups. Personal and family history of atopy was significantly associated with all symptom groups and with the presence of doctor-diagnosed asthma. Smoking, either active or passive, was shown to be significantly associated with current, persistent, and late-onset symptoms. Other factors shown to be significantly associated with certain symptom groups were gender (late-onset wheeze), single-parent households (current cough, persistent cough), social class (late-onset wheeze), number of children in the household (persistent wheeze, late-onset cough), number of furry pets in the household (current wheeze), birth weight (late-onset wheeze), and gas cookers (current wheeze, persistent wheeze). In a subgroup of children studied in more detail in 1987, bronchial hyperresponsiveness in 1987 was positively associated with persistent wheeze in 1995, whereas positive skin-prick testing in 1987 was not.

Prognostic factors for the outcome of childhood asthma in adolescence

By the second decade of life asthma symptoms often abate and it may seem that patients with mild asthma have "outgrown" the disease. Unfortunately this is likely to be the exception rather than the rule. Although the severity of asthma symptoms fluctuates with time, the inherited tendency towards respiratory symptoms never disappears and many teenagers who seem to be free of symptoms do, in fact, have persistent asthma. During symptom-free periods subclinical, but nevertheless significant, airways obstruction and/or bronchial hyperresponsiveness may be present. It is not unusual for adults who have been asymptomatic for a number of years to redevelope asthma symptoms. Indeed, much of the so-called adult onset asthma has its roots in childhood. Levison concluded that, in these subjects, it is often not the asthma that is outgrown but the paediatrician. The more severe asthma is in childhood the more likely it is that the disease will persist in adulthood. A complete list of the characteristics of the disease in childhood, and the potential risk factors associated with an unfavourable prognosis, such as pulmonary function and bronchial responsiveness and markers of airway inflammation, is therefore needed. As properly matched and controlled prospective long term studies have not been published it has not been possible to evaluate the effects on prognosis of any single class of antiasthma agent. Such studies are needed to find out if it is possible to alter the natural history of the disease. In theory modern asthma treatments, because they are able to improve symptoms and underlying disease phenomena, are also beneficial in the long term prognosis of childhood asthma. The majority of patients with persistent asthma included in the currently available studies were not receiving adequate treatment. Since compliance with therapeutic regimens in asthma, especially in adolescence, is low, a monitoring system is needed to guarantee adequate follow up and treatment during and beyond puberty.

Indoor environmental risk factors in young asthmatics: a case-control study

One hundred and ninety three children with asthma and 318 controls aged 1-4 years were evaluated for atopic heredity and exposure to possible indoor risk factors for asthma-for example exposure to furred pets, tobacco smoke, and home dampness. A subgroup of cases were classified as cat and/or dog allergic on the basis of skin prick tests. Heredity for asthma was a significant risk factor (odds ratio (OR) 3.0, confidence interval (CI) 2.1 to 4.6). Environmental tobacco smoke was associated with an excess risk for asthma (OR 1.7, CI 1.1 to 2.3) and signs of home dampness tended to increase this risk (OR 1.3, CI 0.9 to 2.0). High dose exposure to cat and/or dog resulted in an increased risk only in asthma cases sensitised to cat and/or dog (OR 2.7, CI 1.0 to 7.3). A combination of high dose exposure to cat and/or dog, environmental tobacco smoke and damp housing was associated with an OR of 8.0 (CI 1.9 to 34.1). Raised indoor humidity has been shown to reflect low air exchange, which may also lead to increased doses of inhaled aeroallergens and tobacco smoke, and contribute to the interaction between the three risk factors.

Risk factors for the persistence of respiratory symptoms in childhood asthma

We studied the prognosis of childhood asthma in a cohort of 406 children 8 to 12 yr of age when enrolled. Subjects were followed for a mean of 14.8 yr after their initial evaluation, with a follow-up rate of 86%. The mean age at follow-up was 24.7 yr. We assessed the predictive value of sex and various childhood variables on the outcome of symptoms and medication use in adulthood. Although only 19% of subjects were still under a physician's supervision at the time of follow-up, 76% had respiratory symptoms, 32% used maintenance medication, and 22% used medication intermittently. The incidence of cigarette smoking was disturbingly high (33%). In adulthood, women were more likely than men to have symptoms (85 versus 72%, respectively). The childhood symptom severity and the childhood degree of bronchial responsiveness in combination with a low %FEV1 were also related to the outcome of asthma in adulthood. The high prevalence of symptoms in adults at follow-up coupled with the low rate of physician supervision and medication usage suggest that more aggressive treatment may be indicated in asthmatic children.

Lower respiratory tract symptoms in Queensland schoolchildren: risk factors for wheeze, cough and diminished ventilatory function

BACKGROUND

The occurrence of respiratory symptoms and abnormal lung function in children is known to be influenced by genetic and many environmental factors. The association between specific respiratory symptoms in children of school age and their parents has been examined.

METHODS

Respiratory symptoms and ventilatory function were recorded for 4549 schoolchildren in Queensland, Australia.

RESULTS

The cumulative prevalence of wheezing was 23.1% of 8 year olds and 20.8% of 12 year olds, and the prevalence of wheezing within the previous 12 months was 13.9% and 10.5% respectively. A parental history of asthma or wheeze and hayfever was associated with wheeze in the child, but did not affect either the age of onset or frequency of episodes. A history of frequent cough in children who had never wheezed was associated with a parental history of frequent bronchitis, but less strongly with parental wheeze. These familial aggregations were not mediated by common exposure to cigarette smoke. Both a history of parental wheeze and maternal cigarette use were associated with a decrease in FEF25-75 in the child and these effects were additive.

CONCLUSIONS

The association of specific symptoms (wheeze and cough without wheeze) in parent and offspring is interpreted as evidence for different mechanisms of familial transmission, which may be genetic.