A new study has found that a toxic substance, made by certain types of bacteria found in house dust, may reduce the risk of developing the allergic skin condition eczema or wheezing in children if they are exposed to it up to age of 3.
The toxic substance, Endotoxin is an element of the cell wall of gram-negative bacteria, a type of bacteria that repeatedly causes disease. Endotoxin is released when the bacteria dies or is damaged.
The new study found that the lower amount of endotoxin in young children's homes is associated with more wheezing or eczema by age 3,whereas higher amount of endotoxin in their homes,is linked to lower risk of the diseases by age 3.
"We're trying to find why children exposed to endoxotin have lower levels of disease early in life," says researcher Melisa Celaya, M.A., of the Arizona Respiratory Center in Tucson.
Celaya found that certain environmental factors augmented the levels of endotoxin in a home.
Factors and conditions like having a home older than 30 years, substandard home conditions, carpeting, a musty smell and interior wall leaks, were all associated with higher levels of endotoxin.
Blood samples were taken from 484 children enrolled in the Infant Immune Study at different ages, up to 5 years of age.
"We will be looking at the relationship between endotoxin levels in the home and chemicals (called cytokines) that are produced by certain immune system cells, to see why children exposed to lower levels are developing more allergic symptoms later on. This study is unusual in that we are following children over a long period, and are looking at both environmental factors and immunological factors, so we can correlate the two," she says.
The researchers also plan to examine whether genetic predisposition modifies a child's responses to environmental triggers.