Cockroach Allergies in Kids
(Ivanhoe Newswire) – A cockroach allergy is a major contributing factor to asthma in urban children. However, new research is now suggesting that the insect is just a part of a more complex group of factors behind high rates of asthma in an urban environment.
Researchers at the Columbia Center for Children’s Environmental Health at the Mailman School of Public Health suggest that very early exposure to certain components of air pollution can increase the risk of developing a cockroach allergy by age 7 and children with a common mutation in a gene called GSTM may be especially at risk.
"Allergy to cockroach is one of the greatest risk factors for asthma in low-income urban communities. Our findings indicate a complex relationship between allergen and air pollution exposures early in life and a possible underlying genetic susceptibility. Combined, these findings suggest that exposures in the home environment as early as the prenatal period can lead to some children being at much greater risk for developing an allergy to cockroach, which, in turn, heightens their risk of developing asthma,” lead author, Mathew Perzanowski, PhD, was quoted as saying.
Researchers examined 349 mother-child pairs from the Center’s Mothers & Newborns study of environmental exposures in Northern Manhatten and the Bronx. They measured the mother during pregnancy to determine exposure to cockroach allergen. Dust from the kitchen and bed was used to measure the protein in feces, saliva, and other remnants of the cockroach.
The mother’s exposure to polycyclic hydrocarbons (PAH), combustion products that are harmful components of air pollution, was measured through air samples. The presence of the GSTM1 mutation was measured through blood samples. Also, children at ages 5 and 7 had blood tests to identify the presence of IgE antibodies, an immune marker of allergy.
In 279, or 80%, of homes tested positive for high levels of cockroach allergen. At age 7, 82 (30%) of the 264 children that were tested had a cockroach allergy. The higher levels of cockroach allergen led cockroach allergy only in children whose mothers had been exposed to higher levels of PAH during pregnancy. This suggests that PAH enhances their immune response to the allergen.
The combination of the two exposures was even greater in the 27% of children with a common mutation in the GSTM gene, suggesting that minimizing exposure to PAH during pregnancy and to cockroach allergen during early childhood could be helpful in preventing cockroach allergies and asthma in urban areas.
"Asthma among many urban populations in the United States continues to rise. Identifying these complex associations and acting upon them through better medical surveillance and more appropriate public policy may be very important in curtailing this alarming trend,” senior author, Rachel Miller, MD, was quoted as saying.
SOURCE: Journal of Allergy and Clinical Immunology, February 2013