A survey recently carried out in the USA has found that increased exposure to allergens in the home from dog, cat, mouse, cockroach, dust mite, and the fungus Alternaria are associated with increased asthma symptoms in allergic individuals.

The study suggests asthmatics that have allergies may alleviate symptoms by reducing allergen exposures inside their homes. The study also showed that homes with children were less likely to have high allergen levels, perhaps because homes with children may be cleaned more frequently than homes without children. Regular household cleaning is a simple yet effective regime that helps to reduce the overall exposure burden.

The researchers suggest that while reducing allergen levels in the home may not prevent individuals from developing asthma, reducing exposure levels is crucial for those whose asthma is allergic in nature.

The work was carried out by researchers at the National Institute of Environmental Health Sciences, the University of Iowa, Rho Inc., and the Constella Group who surveyed the homes of nearly 2500 individuals in 75 locations throughout the USA. The findings are published online and available in the March issue of the Journal of Allergy & Clinical Immunology.