Environmental factors and symptoms in infants at high risk of allergy.

Abstract

Study objective: To identify environmental determinants of six symptoms associated with allergic disease in infancy. Design: Infants were participants in a prospective randomised controlled trial of feeding practices in families with a history of atopy. Setting: Infants were recruited in two maternity hospitals in S Wales and followed up in the community for 1 year. Participants: Mothers of 519 infants agreed to participate, but 36 were excluded (mainly for moving home or failing to attend for follow-up), leaving 483 in the study (253 male, 230 female). Infants were followed up and examined for evidence of allergic disease at 3, 6 and 12 months. Measurements and main results: At each examination, mothers were questioned about episodes of illness in the infant, and the data presented relate to (reported and observed) eczema and nasal discharge, and (reported) wheeze, prolonged colds, diarrhoea and vomiting. Mothers kept a diary with details of feeding for the first 6 months. All homes were visited by a nurse who took samples of dust for dust mite antigen analysis. Extensive socio-demographic data were collected. None of the factors studied showed a convincing relationship with eczema. In a multiple logistic regression analysis breast feeding appeared to protect against wheeze, nasal discharge, colds, vomiting and diarrhoea. Having more siblings increased the likelihood of prolonged colds, and (together with overcrowding) ofwheeze and nasal discharge. Maternal smoking and low social class were associated with wheeze, and house dust antigen with prolonged colds. Respiratory symptoms were associated with some aspects of housing but these could not be distinguished clearly from other social factors. Babies born in Autumn were at increased risk of wheeze, vomiting and diarrhoea. Conclusions: Environmental factors play an important part in determining risk of symptoms in potentially atopic babies. These factors are in principle open to manipulation.Social and environmental factors appear to have an important relationship with disease in infancy. The infant mortality rate in 1981 for legitimate births in England and Wales showed a continuous gradient from 7-7 per thousand live births in social class I to per thousand in social class V.' Presumably this gradient represents a potential for improving the health of infants in lower social classes if only the adverse factors could be identified and corrected.Allergic disease has a strong genetic component: children born to atopic parents have a higher incidence of asthma and wheezing than other children.Environmental factors also seem to be involved, since the concordance rate for allergy in monozygotic twins is less than 100%. This paper presents data obtained during the first year of life from a cohort of infants in atopic families, showing how various environmental factors were related to the development of symptoms.Methods

The relationship between asthma admission rates, routes of admission, and socioeconomic deprivation

“…However, although we are aware of the ecological fallacy of assuming that higher admission rates in more deprived communities necessarily indicates that there is a higher admission rate for poorer individual patients, there are a number of environmental factors which may also contribute to an association between asthma morbidity and poverty. Asthma may be exacerbated by damp [44,45] or mouldy [46] housing conditions, although the evidence is not conclusive [47]. Smoking and passive exposure to cigarette smoke in the home is more common among people in lower income groups [13,48], and may increase the morbidity among asthmatics [49].…”

Passivrauchen [MAK Value Documentation in German language, 1998]

“…In mehreren epidemiologischen Studien wurde bei Säuglin-gen und Kleinkindern für das Auftreten von respiratorischen Erkrankungen, wie Lungenentzündung und Bronchitis erhöhte relative Risiken von 1,4-4,8 festgestellt (Fergusson und Horwood 1985;Hall et al 1984;Harlap und Davies 1974;Leeder et al 1976;Ogston et al 1987;Pullan und Hey 1982;Rantakallio 1978). Ferner traten in Kohortenstudien, speziell bei Kindern mit atopischer Prädisposi-tion, Bronchitis und Asthma signifikant häufiger auf, wenn diese zuhause gegenüber ETS exponiert waren (Arshad und Hilde 1992;Bisgaard et al 1987;Halken et al 1991;Martinez et al 1992;Neuspiel et al 1989;Rantakallio 1978;Taylor und Wadsworth 1987;Burr et al 1989;Cogswell et al 1987;Geller-Bernstein et al 1987;Halken et al 1992). Es kommt im späteren Leben der Kinder oft zur gesundheitlichen Verbesserung, wenn die Eltern nicht mehr in Gegenwart der Kinder rauchen (Murray und Morrison 1993).…”

Prevention of asthma

“…Such infections are, in themselves, a risk factor for the later development of asthma [71][72][73][74][75], but it is not known whether they lead to the development of asthma or are the first expression of an asthmatic phenotype. There is evidence that exposure to ETS increases the risk of wheeze in infants and children, with an odds ratio of approximately 1.5-3.0 [59,63,70,[76][77][78][79][80][81][82].…”