Asthmatic Kids Under a Cloud

Half a century ago, when Pigpen was new to the Peanuts gang, Charlie Brown asked him the obvious question: “Pig-Pen, why are you always so dirty?” Pig-Pen, answered with his face ringed with grime, “I have affixed to me the dirt and dust of countless ages.”

He isn’t the only one. Research shows that even kids as clean as Charlie Brown are enclosed in invisible halos of dirt and dust that can be detected using small personal monitors. For children with allergic asthma, that can be a problem.

Lead author, Nathan Rabinovitch, of the National Jewish Medical and Research Center in Denver, states that “each kid has his own individual pollution cloud.” What’s in this cloud depends on what’s in their house, their school, and what their daily experience entails. Even serious scientists have started to call this phenomenon the Pigpen Effect, referring to the Charles Schulz character of the 1950’s.

Scientists have known for a long time that dust and dirt make allergies worse, especially in inner-city urban areas. A study of 1,528 children, financed by the National Institutes of Health, found that a child’s symptoms and cost of care can be significantly reduced by spending a $1,469 per family on counseling, cleaning and buying supplies, such as impermeable mattress and pillow covers.

However, while many studies of inner-city kids have focused on allergens in the home, Rabinovitch, instead, chose to focus his study of the Pigpen Effect on a highly allergenic protein called an endotoxin. Endotoxin, one component of the pollution cloud, comes from bacteria that are everywhere in the environment, including on pets.

Researchers are baffled by the fact that kids that have asthma are better or worse, one day to the next. They hoped to discover why and to answer a related asthma management question: How do pets complicate a child’s asthma, even when the child is involved in activities outside of the home?

A curious wrinkle to this study comes from other research that has shown that exposure to lots of endotoxin before allergy develops, usually through insect dust, pets and animals, can actually be protective – priming the immune system to become tolerant of the things that often promote allergy. This theory is part of the “Hygiene Hypothesis.” Multiple studies have suggested that this hypothesis is grounded in fact. However, it becomes murky when some kids are allergic, even when they are exposed to endotoxin from cockroaches and dust mites when they are younger. The Hygiene Hypothesis also doesn’t explain why kids who have asthma get better or worse from day to day.

The distinction between the Hygiene Hypothesis and the tendency for asthma to wax and wane is an important one, according to Rabinovitch, since once a person has allergies, dust, dirt, and pets make matters worse.

Researchers studied students ages 6 to 13 who attended a National Jewish’s Kunsberg School. These were children whose asthma would interfere with their performance and attendance in ordinary schools. Each child was fitted with a monitor equipped with a filter that would capture airborne endotoxins. Asthma severity was measured by their breathing, and by asking the children to log severity of their symptoms using a daily scoring system. Researchers then compared readings from their monitors, with those monitors in the environment.

The monitors showed that personal exposures to endotoxin were “significantly higher” than the levels kids were exposed to in the environment, supporting the notion that children, like Pigpen, are surrounded by a personal cloud. “One kid may have a very different exposure than a second kid,” Rabinovitch says.

The final result: The bigger the child’s endotoxin cloud, the more airway obstruction they had to endure, researchers reported in the Journal of Allergy and Clinical Immunology.

Even if exposed at a young age, “Pets are not good for asthma,” according to Rabinovitch. If you play with a cat or a dog on a given day, you will get a high dose of endotoxin. If you live with a cat or dog, you will get the maximum dose.

(Summarized from USA Today: Article by Steve Sternberg)