Kids who sneeze at cats may develop asthma: study

NEW YORK (Reuters Health) - Children who are sensitive to cats appear to have an increased risk of developing asthma or hay fever as young adults, study findings suggest.

Among a group of children showing signs of being allergic to cats at age 11, one in five (20 percent) developed asthma and 47 percent developed hay fever over the next 9 years on average, researchers report in the journal Allergy.

Dr. Torsten Shaefer, of the Medical University Lubeck, Germany, and colleagues assessed the incidence of asthma and hay fever among 1,207 individuals who, as school children, had been tested for sensitivity to the common allergens birch tree pollen, grass pollen, household dust mites, mold, and cats.

Of all these allergens, only sensitization to cat was associated with a significantly increased risk of developing asthma, the investigators report.

Overall, 20 percent of those testing positive to cat allergen, compared with about 11 percent testing positive to grass pollen or Cladosporium mold, developed asthma during the next 9 years.

By contrast, the development of hay fever was generally associated with sensitivity to each of the tested allergens. But, after the investigators adjusted for the participant's sensitivity to all the allergens, only cat and grass pollen sensitivity remained significantly associated with the development of hay fever.

Of the children who tested positive to cat allergen and grass pollen at age 11, hay fever developed, over the next 9 years, in 47 and 42 percent, respectively.

Respiratory allergies are a major health problem among children and young adults, Shaefer and colleagues note in their report. Those sensitized to allergens, but not yet affected with respiratory allergies, have a higher risk of developing asthma or hay fever at an older age.

The results of the current study, they say, suggest that childhood sensitization to cat and grass pollen predicts the incidence of asthma and hay fever over time.

SOURCE: Allergy, November 2007