New Research On The Origins Of Asthma And Allergies Presented At Annual Meeting

Main Category: Allergy
Also Included In: Respiratory / Asthma
Article Date: 15 Mar 2008 - 6:00 PDT

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Viral illnesses that produce wheezing are very common in early childhood, but not all children who wheeze in the first several years of life go on to develop asthma. D.J. Jackson, MD and colleagues at the University of Wisconsin, Madison presented their study at the 2008 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting in Philadelphia.

Wheezing with respiratory syncytial virus (RSV) infections has previously been associated with increased risk of developing asthma later in childhood. Jackson and colleagues confirmed this finding, but discovered a novel finding as well: wheezing illnesses during the first three years of life caused by rhinovirus, the most common cause of "colds" in children and adults, were the strongest predictor of asthma at age 6 years.

Exposure to diesel exhaust particles and indoor endotoxin during early childhood increases the risk for persistent wheeze at age three

Diesel exhaust particles (DEP) and endotoxin, found in bacteria, may act together to promote wheezing in young children, according to a new study presented at the 2008 AAAAI Annual Meeting in Philadelphia.

Children enrolled in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), a NIEHS sponsored study, were evaluated at age 3. Exposure to high levels of DEP prior to age 1 was associated with a two-fold increased risk for wheezing. Children exposed to both DEP and high levels of endotoxin were at risk for wheezing at age three.

Patrick Ryan, PhD and colleagues at the University of Cincinnati in Cincinnati, Ohio concluded that children exposed to DEP during infancy may be at increased risk for the development of wheezing at age 3, and this relationship is modified by indoor exposure to endotoxin.

Allergens in urban elementary schools and homes of children with asthma

William Sheehan, MD and colleagues at Children's Hospital Boston, Boson, MA studied the association between allergens in schools and childhood asthma. They investigated allergen exposure in schools compared to homes with a specific focus on children with asthma. This new study was presented at the 2008 AAAAI Annual Meeting in Philadelphia.

The study was based on collecting 66 samples from various rooms in four Northeastern US urban elementary schools and 38 student bedrooms. Samples were analyzed for cat, dog, cockroach, dust mites, and mouse urinary protein.

The study, presented at the 2008 AAAAI Annual Meeting in Philadelphia, shows higher levels of mouse urine, but lower levels of dust mites in schools versus homes. It is important to recognize that children with asthma may encounter varying levels of allergens in environments outside the home, such as schools.

Exposure to mouse allergens in US homes is associated with asthma symptoms

Asthma, which remains a significant public health concern in the U.S., affects millions of Americans. To evaluate the importance of mouse allergen in asthma, Päivi Salo, PhD and colleagues at the National Institute of Environmental Health Sciences examined whether elevated levels of mouse allergen were associated with asthma among the study participants.

Results from a national survey demonstrate that elevated mouse allergen levels in the home are associated with asthma symptoms in allergic individuals. The National Survey of Lead and Allergens (NSLAH) was the first study to estimate mouse allergen levels and examine residential exposure to mouse allergen in a nationally representative sample of U.S. households. The study confirms that mouse allergen is an important household allergen and aggravates asthma symptoms among asthma sufferers.

Although mouse allergen is a well-recognized allergen in occupational settings, it has only recently been recognized as an important allergen in homes. To date, the majority of the research has focused on inner-city homes in which mouse allergen has been found to be ubiquitous. The findings from the NSLAH suggest that the presence of mouse allergen in U.S. homes is surprisingly common even outside urban areas. Of the surveyed homes, 82% had detectable levels of mouse allergen and, in 35% of the homes; allergen concentrations exceeded a level that has been associated with increased mouse allergen sensitization rates. Elevated levels were most commonly found in high-rise apartments and mobile homes, older homes, and low-income homes.

The results showed that in allergic individuals, higher levels of mouse allergen significantly increased the likelihood of having asthma symptoms. Because elevated levels of the allergen were not restricted to inner-city areas, this study suggests that mouse allergen is an important household allergen outside of urban environments. For allergic individuals, reducing allergen levels in the home is an essential part of asthma control and treatment. Therefore, mice may not be welcome visitors in homes where allergic and asthmatic individuals reside.

Health care utilization is higher among patients whose asthma is not well-controlled

The study by Theresa Guilbert, MD and colleagues aimed to determine whether asthma control is associated with increased healthcare resource utilization. This new study was present at the 2008 AAAAI Annual Meeting.

The study interviewed patients receiving any prescription asthma treatment in the past year. Patients whose asthma was not well-controlled at baseline had a higher risk of an asthma-related event compared to patients with controlled asthma. Adults with asthma that was not well-controlled were at 4-times greater risk for office visits and 4.5 times greater risk for ER visits. Children with asthma that was not well-controlled were at 4-times greater risk for office visits and tended to have an increased risk of ER visits.

Asthma that is not well-controlled is associated with increased healthcare resource utilization. Asthma control determination using ACT/C-ACT may help clinicians and patients decrease the risk of these events. Additional studies to determine if monitoring asthma control could lead to reduced healthcare resource utilization could be valuable.

These studies were presented at the 2008 Annual Meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI). The AAAAI is the largest professional medical specialty organization in the United States representing allergists, asthma specialists, clinical immunologists, allied health professionals and others with special interest in the research and treatment of allergic disease.

Allergy/immunology specialists are pediatric or internal medicine physicians who have elected an additional two years of training to become specialized in the treatment of asthma, allergy and immunologic disease.

The AAAAI represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Allergy/immunology specialists are pediatric or internal medicine physicians who have elected an additional two years of training to become specialized in the treatment of asthma, allergy and immunologic disease. Established in 1943, the AAAAI has more than 6,500 members in the United States, Canada and 60 other countries.

American Academy of Allergy, Asthma & Immunology