Mouse, Cockroach Sensitivity Common in Children With Asthma

December 7, 2011 (Cancun, Mexico) — More than one third of children admitted to the hospital for bronchodilator-responsive wheezing or asthma were sensitized to cockroach or mouse allergens.

Cockroach allergen sensitization was lower in children from higher-income homes, but surprisingly, mouse sensitization tended to be slightly higher in high-income families than in low-income families, although this finding did not reach statistical significance. The findings were reported here at the World Allergy Organization XXII World Allergy Congress (WAC).

Between August 2010 and February 2011, the researchers enrolled 416 children in a prospective study. Participants were aged 1 to 16 years and had been admitted for bronchodilator-responsive wheezing or acute asthma to a children’s hospital that accepts more than 90% of all asthma admissions in its county. The children were tested for cockroach and mouse sensitization by using specific IgE. The researchers interviewed caregivers to determine sociodemographic characteristics and asthma history.

In all, 65% of participants were African American, 76% were publicly insured, 78% had a household income less than $60,000, and 81% had been previously diagnosed with asthma.

The investigators found that 34% of children were sensitized to cockroach or mouse allergens (16% mouse, 26% cockroach, 8% both). The researchers found a correlation with age: patients younger than age 4 years were less likely to be sensitized to cockroach (10% vs. 34%; P < .0001) and mouse (8% vs. 20%; P = .002) than were older participants.

There was also a correlation with a previous asthma diagnosis: those with such a diagnosis were more often sensitized to cockroach (29% vs. 13%; P = .007) and mouse (13% vs. 9%; P = .06) than were patients with no such previous diagnosis.

Cockroach sensitization was more common in children in families earning less than $15,000 than in those from families that earned $90,000 or more (33% vs. 18%; P = .01). There was a trend toward more sensitization among children in the affluent group, but the numbers (10% vs. 17%) did not reach statistical significance, the authors said when reporting their findings.

“We found that [mouse and cockroach sensitization] was very common, and we know [cockroach sensitization] is associated with worse asthma,” Terri Moncrief, MD, an instructor at Cincinnati Children’s Hospital Medical Center, Ohio, who presented the research, told Medscape Medical News.
The research underscores the importance of allergy testing, especially for high-risk children. “If they test positive during hospitalization or during assessment for asthma, they should definitely seek counsel with an allergist or immunologist. We can help avoid the exposure if possible by [removing] the allergen from the home, and there are medications that can be used to decrease the response to the sensitizing allergen, or we can induce tolerance with allergy shots,” Dr. Moncrief added.

“The study was very interesting. One would anticipate that mouse allergen would be a risk factor for allergy in the inner city, [but] this is not showing that it relates to socioeconomic categories,” Myron Zitt, MD, clinical associate professor of medicine at the State University of New York in Brooklyn, who co-moderated the session, told Medscape Medical News.

Dr. Moncrief and Dr. Zitt have disclosed no relevant financial relationships.
World Allergy Organization XXII World Allergy Conference (WAC): Abstract 2197. Presented December 5, 2011.

Medscape Medical News from the:
World Allergy Organization XXII World Allergy Congress (WAC)
Jim Kling