麻豆传媒

All children with persistent asthma symptoms should be tested for indoor allergens and pollutants, such as dust mites and second-hand cigarette smoke, suggested a new clinical report from the American Academy of Pediatrics.

Awareness of specific triggers could help pediatricians to create individually tailored environmental control measures to reduce asthma symptoms in children with minimal use of medications, wrote , of Johns Hopkins Hospital in Baltimore and colleagues, authors of the new guidance in the November issue of .

In an interview, Matsui said, "Allergy test results help to identify allergens in the home that contribute to the child's asthma symptoms and exacerbations.

"We know that targeting all exposures that can trigger a child's asthma is more likely to be successful and to result in significant improvement than targeting only one or two of them, and can help reduce asthma attacks and the need for medication."

According to the report, an assessment of a child's individual environmental history should be an integral part of asthma management. The authors urged pediatricians to ask families about exposure to the following common triggers:

• Dust mites and mold: An estimated 30-62% of children with persistent asthma are allergic to dust mites, and about half are sensitive and exposed to mold.
• Furry pets: Cats and dogs are common furry pets found in homes, yet up to 65% of children with persistent asthma report being allergic.
• Presence or evidence of pests such as cockroaches and rodents: Cockroach allergen exposure was first linked to asthma morbidity in children in 1997, and the link has been replicated ever since. Nearly 75-80% of U.S. homes contain detectable amounts of mouse allergen. Concentrations in homes in neighborhoods with high poverty rates are up to 1,000-fold higher than those found in suburban homes.
• Indoor air pollution: Cigarette smoke is a major indoor trigger, with nearly 30% of all U.S. children and 40-60% of U.S. children in low-income households exposed to second-hand smoke in their homes. Additionally, the use of older wood-burning stoves, unvented space heaters, and other sources of combustion can produce nitrogen dioxide and other pollutants which are known to exacerbate asthma symptoms.
• Household chemicals: Common household items such as air fresheners and cleaning agents include chemicals that can be respiratory irritants and trigger asthma symptoms.

The report also recommended use of allergen-specific blood antibody tests, or a referral to an allergist for skin testing, in order to identify indoor allergens likely to contribute to a child's asthma.

"Which exposures to focus on will be informed by questions the pediatrician asks of the family," Matsui said. "Asking about pets will identify children who may have pet allergen exposure contributing to their asthma. Similarly, asking about signs of mouse or cockroach infestation will indicate which children might be at risk from these exposures."

Additionally, pediatricians should routinely ask about second-hand smoke exposure as this will guide further discussion about ways to eliminate or reduce a child's exposure to smoke, she said.

However, not all exposures can be identified by querying families, she cautioned: "Dust mites ... they are microscopic. Allergy testing will reveal if a child is allergic to dust mites, and if so, dust mite precautions can be recommended. In some arid regions of the country, however, dust mite exposure is very low and not likely relevant."

Once triggers are identified, pediatricians can tailor environmental control strategies -- such as source removal, source control, and mitigation strategies -- to each potentially relevant indoor exposure.

For example, the best way to reduce or eliminate tobacco smoke exposure was smoking cessation by close family members and caregivers. "Once these exposures are removed, children typically have a marked improvement in their asthma and can have reduced need for medications," Matsui said.

High-efficiency particulate air purifiers and allergen-proof mattress and pillow encasements were cited in the report as effective mitigation strategies for dust mites.

Matsui et al also highlighted the importance of education: "Primary care pediatricians, allergists, pediatric pulmonologists, other health care workers, or community health workers trained in asthma environmental control and asthma education," should all be prepared to communicate knowledge on triggers.

And although many insurers do not currently cover environmental assessments and control measures, there are both public and private resources available to aid pediatricians, specialists, and patients with environmental remediation efforts.