No abstract

The determinants of wheezing and allergy were investigated in 453 children with a family history of allergic disease. A randomised controlled trial examined the effects of withholding cows' milk protein during the first three months of life and replacing cows' milk with soya milk. The children were followed up to the age of 7 years. Withholding cows' milk did not reduce the incidence of allergy or wheezing. Children who had ever been breast fed had a lower incidence of wheeze than those who had not (59% and 74% respectively). The effect persisted to age 7 years in the nonatopics only, the risk ofwheeze being halved in the breast fed children after allowing for employment status Wheezing is a common symptom in childhood. Its causes include infection, allergy, and exposure to atmospheric irritants such as tobacco smoke. In 1982 a study was set up to investigate prospectively the onset of wheezing in a cohort of children from birth.'2 The children were selected so as to have a high risk of wheezing illness in two respects: they lived in an area (two valleys in South Wales) known to have a high prevalence of chest disease,3 and they all had a parent or sibling with a history of atopic disease.One objective of the study was to examine the possibility4 that withholding cows' milk protein for young infants at high risk of allergy reduces their incidence of asthma. To this end, a randomised controlled trial was conducted in which half the babies were given soya milk instead of cows' milk preparations; no evidence of benefit emerged during the first year of life. ' A further objective of the study was to observe the relationship between various other factors and the development of respiratory symptoms during childhood. Breast feeding was found to be associated with a reduced incidence of wheeze during the first year of life, and this reduction was not attributable to social class, parental smoking habit, or number of siblings, although these factors all had some independent prognostic effects. These and other results from the first year have already been published.' 25 The children have now been followed up to the age of 7 years, and this paper presents the findings at that time. MethodsWomen attending antenatal clinics were asked whether they, their husbands, or their children had ever had asthma, eczema, or hay fever and those who replied affirmatively were invited to take part in this study. The women were randomly allocated to an intervention group, which was supplied with soya milk as an alternative to cows' milk formulation when the baby was born, and a control group, which was not. Mothers in the intervention group were asked to avoid giving the baby any food containing cows' milk protein for four months, and advised to restrict their daily milk intake to half a pint (284 ml) during the pregnancy and while they were breast feeding. Information was collected about the feeding of the infants (including the duration of breast feeding) and other potentially relevant factors.' 2 Samples of dust were taken fro...

Allergic disease in childhood is to a large degree determined before birth or during infancy.

The location of IgE synthesis has been a longstanding controversy, with previous evidence favoring either the mucosa or lymphoid tissue in the region of allergen entry. The evidence for IgE synthesis in mucosal tissues has always been circumstantial. We have developed a novel explant culture system, using ELISA and radioactive amino acid incorporation, to measure de novo IgE protein synthesis in the nasal mucosa of hay fever patients. Surprisingly, IgE synthesis continues between seasons in the explants from grass pollen‐sensitive patients and a higher proportion of this IgE compared to serum IgE is allergen specific. Persistent IgE synthesis may ensure the expression of immediate hypersensitivity in the mucosa and promote rapid amplification of the allergic response in the local lymphoid tissue on allergen provocation. Our work demonstrates definitively for the first time that the local mucosa is a site of ongoing IgE synthesis.

Objectives-To find the nature and incidence of symptoms experienced by a large sample of hospital endoscopy nurses. To find whether nurses in endoscopy units develop asthma under current working conditions in endoscopy units. To obtain analytically reliable data on exposure concentrations of glutaraldehyde (GA) vapour in endoscopy units, and to relate them to individual hygiene and work practices. To characterise any exposureresponse relations between airborne GA and the occurrence of work related symptoms (WRSs). Due to the growing concern about the perceived increase in WRSs among workers regularly exposed to biocides, all of whom work within a complex multiexposure environment, a cross sectional study was designed. Methods-Current endoscopy nurses (n=348) from 59 endoscopy units within the United Kingdom and ex-employees (who had left their job for health reasons (n=18) were surveyed. Symptom questionnaires, end of session spirometry, peak flow diaries, skin prick tests (SPTs) to latex and common aeroallergens, and measurements of total immunoglobulin E (IgE) and IgE specific to GA and latex were performed. Exposure measurements included personal airborne biocide sampling for peak (during biocide changeover) and background (endoscopy room, excluding biocide changeover) concentrations. Results-All 18 ex-employees and 91.4% of the current nurses were primarily exposed to GA, the rest were exposed to a succinaldehyde-formaldehyde (SF) composite. Work related contact dermatitis was reported by 44% of current workers exposed to GA, 56.7% of those exposed to SF composite, and 44.4% of ex-employees. The prevalence of WRSs of the eyes, nose, and lower respiratory tract in current workers exposed to GA was 13.5%, 19.8%, and 8.5% respectively and 50%, 61.1%, and 66.6% in the ex-employees. The mean percentage predicted forced expired volume in 1 second (ppFEV 1 ) for ex-employees (93.82, 95% confidence interval (95% CI) 88.53 to 99.11) was significantly lower (p<0.01) than that of current workers exposed to GA ( Ex-employees and current workers with WRSs warrant further study to elucidate the cause and mechanisms for their symptoms. Ventilation systems used for the extraction of aldehydes from the work area may be less eVective than expected and due to poor design may even contribute to high peak exposures. (Occup Environ Med 2000;57:752-759)