You’re probably aware that childhood asthma is on the increase for reasons not well understood. Asthma is now the most common disease of children, affecting up to 15% of children in the U.S. Most of the young victims of asthma live in inner cities and in homes that may be old and in poor repair. In cities, there can be several factors contributing to the breathing problems of asthma, ranging from mold, to airborne pollutants, to pets, or allergens from dust mites or cockroaches, to name a few.

Mice Are a Universal Problem in City Structures

Most people are aware that cockroach infestations can be a cause of allergic reactions or asthma in children that live with roaches. That connection has been well documented (see Cockroach Allergen is a Very Real Problem). Several years ago, researchers discovered that the presence of mice in homes was also a contributing factor to asthma in children. In fact, it turns out that mouse infestations cause more asthma symptoms than cockroach infestations or dust mites or pets.

Mice shed protein particles or allergens in their urine and also in dry skin flakes or dander. These tiny particles become airborne and are inhaled, causing asthmatic wheezing or breathing problems in children that have become sensitized to the allergens.

When inner-city children and their homes were studied, mouse allergens were present at some level in 95% of the homes tested. Mouse allergens are most common in high-rise apartments, older homes, and mobile homes. The older the structure, the more likely that mouse allergens are present since older homes or apartment buildings have more gaps and openings allowing mice inside and providing them with travel routes throughout the building.

Mouse Problems Can Be More Serious in Schools Than Homes

Asthma is the leading cause of school absenteeism. One study found that children with asthma missed 3 times as many school days as their classmates without asthma. A surprising finding is that the schools themselves may contribute to the problem. When dust samples from inner-city schools were analyzed for allergens, almost 100% of the samples contained mouse allergens—and at higher levels than in children’s homes. Cockroach, dust mite, and pet allergens were present but not at significant levels.

Pest Allergens Are Difficult to Remove

This means that schoolchildren can be exposed to mouse allergens in their homes and then the exposure continues during the 7-8 hours that they are at school. Part of the problem is that eliminating the mice or cockroaches doesn’t get rid of existing allergens, and even cleaning can’t remove all of the allergens that are hidden in wall voids or cracks and crevices (see Cockroach Allergen Levels Remain Despite Efforts).     Enough allergen can remain to still cause asthmatic reactions in the very sensitive.

This scenario emphasizes the importance of not allowing mice or cockroaches, and their allergens, to build up in the first place (see Mice Moving into Homes Can Bring Allergens With Them!). Pest-proofing or sealing openings, routine inspections to detect pests, and improved sanitation measures are the first lines of defense in preventing childhood asthma.

Photo Credit : By The U.S. Food and Drug Administration – https://www.flickr.com/photos/fdaphotos/7349095984, Public Domain, Link