An association between plastic mattress covers and sheepskin underbedding use in infancy and house dust mite sensitization in childhood: a prospective study

Sleeping on animal fur is related to asthma outcomes in later childhood

Animal furs might represent a "proxy" for high and diverse microbial exposures within a critical time window of immune development. We assessed whether sleeping on animal fur shortly after birth is associated with asthma and atopy up to the age of 10 years. LISAplus participants (n=2441) from Munich and Leipzig, Germany, were included in the analysis. Animal fur exposure, cofactors and health outcomes were obtained periodically up to 10 years of age by parental questionnaires. Information on specific IgE to aeroallergens was available at 10 years. Cytokine-producing peripheral T-cells were assessed in a subgroup of children at 2 and 3 years. Confounder-adjusted associations were evaluated using logistic regression analyses. Sleeping on animal fur was very common (55%). In adjusted logistic regression analyses, sleeping on animal fur was inversely associated with recurrent early wheezing at 4 years (adjusted OR 0.75, 95% CI 0.61-0.93) and current asthma at 6 years (adjusted OR 0.56, 95% CI 0.31-1.01). Furthermore, sleeping on animal fur during the first 3 months of life was significantly associated with a persistently stimulated interferon-γ response until the age of 3 years. Animal fur could be an effective measure of creating environments associated with higher microbial exposure.

Adherence to allergy prevention recommendations in children with a family history of asthma

Allergen avoidance has been a major component of most programs for primary prevention of asthma and allergic diseases in childhood. As a part of the Childhood Asthma Prevention Study, families were provided with written and oral information on measures considered to be helpful in the primary prevention of allergic disease in high-risk infants. Dietary measures included advice to breastfeed for 6 months or longer, to delay the introduction of solid foods until after the infant turned 6 months of age, and to delay giving allergenic foods (egg and peanut butter) until after 12 months of age. In the active group of the randomized controlled trial aimed at reducing house dust mite (HDM) allergen levels, parents were advised to use an HDM-impermeable study mattress cover and an acaricide, to avoid sheep skins, and not to use a pillow before 12 months of age. Families received regular visits from the research nurses at 1, 3, 6, 9 and 12 months and phone calls every 6 wk. Only 43.4% of mothers were breastfeeding by 6 months and less than 20% by 12 months. The introduction of solid foods before 6 months was common, 26% by 3 months and 96% by 6 months. Adherence to infant-feeding recommendations was significantly greater in women over 30 yr of age, women who did not smoke during pregnancy, and women who had a tertiary education. Adherence to HDM reduction measures was greater than to those for infant feeding. The presence of symptoms in the form of an itchy rash by 4 wk did not significantly increase adherence. Complete adherence to infant-feeding recommendations in this intervention study of high-risk infants was low despite the provision of written information and reinforcement at home visits. In considering allergy prevention advice offered during clinical care, the likelihood of adherence is a factor which needs to be evaluated in assessing any potential benefits of allergy prevention regimens.

Indoor residential chemical emissions as risk factors for respiratory and allergic effects in children: a review

Most research into effects of residential exposures on respiratory health has focused on allergens, moisture/mold, endotoxin, or combustion products. A growing body of research from outside the US; however, has associated chemical emissions from common indoor materials with risk of asthma, allergies, and pulmonary infections. This review summarizes 21 studies in the epidemiologic literature on associations between indoor residential chemical emissions, or emission-related materials or activities, and respiratory health or allergy in infants or children. Associations, some strong, were reported between many risk factors and respiratory or allergic effects. Risk factors identified most frequently included formaldehyde or particleboard, phthalates or plastic materials, and recent painting. Findings for other risk factors, such as aromatic and aliphatic chemical compounds, were limited but suggestive. Elevated risks were also reported for renovation and cleaning activities, new furniture, and carpets or textile wallpaper. Reviewed studies were entirely observational, limited in size, and variable in quality, and specific risk factors identified may only be indicators for correlated, truly causal exposures. Nevertheless, overall evidence suggests a new class of residential risk factors for adverse respiratory effects, ubiquitous in modern residences, and distinct from those currently recognized. It is important to confirm and quantify any risks, to motivate and guide necessary preventive actions.

PRACTICAL IMPLICATIONS

Composite wood materials that emit formaldehyde, flexible plastics that emit plasticizers, and new paint have all been associated with increased risks of respiratory and allergic health effects in children. Although causal links have not been documented, and other correlated indoor-related exposures may ultimately be implicated, these findings nevertheless point to a new class of little recognized indoor risk factors for allergic and respiratory disease, distinct from the current set of indoor risk factors. The available evidence thus raises initial questions about many common residential practices: for instance, using pressed wood furnishings in children's bedrooms, repainting infant nurseries, and encasing mattresses and pillows with vinyl for asthmatic children. The findings summarized here suggest a need for substantially increased research to replicate these findings, identify causal factors, and validate preventive strategies.

Infant sleeping environment and asthma at 7 years: a prospective cohort study

OBJECTIVES

We investigated the role of infant bedding items, as part of a composite bedding environment, in the development of childhood wheezing.

METHODS

This prospective cohort investigation involved 863 children who participated in an infant survey in 1988 and an asthma study in Tasmania, Australia, in 1995. The derived 3 composite infant bedding categories corresponded to increasing numbers of house dust mite (HDM)-rich bedding items used. Outcomes measured included recent and frequent wheezing.

RESULTS

Composite infant bedding used was associated with recent wheezing. Effects increased at increasing levels of HDM-rich bedding items used. Effects were further enhanced by home environmental factors of bedroom heating, recent bedroom painting, and absence of bedroom carpeting. When any 2 or more of these environmental factors were present, a strong dose-response relationship was evident.

CONCLUSIONS

Our results show that bedding exposures in infancy are prospectively associated with childhood wheezing and that home environmental conditions may modify this association.

A prospective association between cocoon use in infancy and childhood asthma

There is increasing evidence for a role for bedding items in the development of asthma. The use of some forms of synthetic bedding, such as foam mattresses and pillows, is associated with a significantly increased risk of childhood wheeze. Our aim was to examine prospectively whether the use of synthetic cocoon/baby nests in infancy is associated with the subsequent development of wheeze in childhood. Data collected in 1988 as part of the Tasmanian Infant Health Survey were linked to the cross-sectional Childhood Asthma Survey conducted in 1995 in Tasmania, Australia. We were able to match 863 records out of the 1111 in the 1988 survey. Information including parental, child-care, and the infant's sleeping environment was collected at home interview in 1988 when the infant was 1 month of age. Data including sleep environment and asthma symptoms were available for each child at age 7 years. A generalised linear model was used to calculate the adjusted relative risk (RR) estimates for symptoms of wheeze and infant cocoon use. For children who were placed in a cocoon in infancy, there was an increased risk of recent wheeze (adjusted RR = 4.33 [95% CI 2.08, 9.02]) and night wheeze (adjusted RR = 3.35 [95% CI 1.52, 7.39]) at age 7 years. In view of the increasing prevalence of childhood asthma, the identification of potentially modifiable environmental factors which might operate in infancy is of importance. The present findings implicate infant bedding choice as a significant factor and further studies on the infant sleeping environment are indicated.