Environmental and occupational respiratory disorders
Longitudinal study on cat allergen exposure and the development of allergy in young children

https://doi.org/10.1016/j.jaci.2007.02.017Get rights and content

Background

The influence of cat allergen exposure in early childhood on the development of sensitization and allergic diseases is complex. Little is known about the natural course of the sensitization development within individuals.

Objective

We investigated the association between cat allergen exposure in infancy and cat ownership and cat contact during childhood and the development of cat sensitization and allergic diseases up to age 6 years using a longitudinal analysis approach.

Methods

Overall, 2166 children from an ongoing birth cohort study were included in the analysis. House dust samples were collected 3 months after birth. Cat allergen levels were extracted. Blood samples were collected when the children were 2 and 6 years old. Information on the allergic symptoms of children and doctor-diagnosed allergic disease were collected at each follow-up using questionnaires.

Results

Cat allergen exposure in infancy was positively associated with sensitization at age 2 years but not at age 6 years. No associations existed between cat allergen exposure in infancy and allergic symptoms and diseases up to age 6 years. Cumulative allergen exposure from cat ownership and regular cat contact increased the risk of cat sensitization up to age 6 years.

Conclusion

Cat allergen exposure in infancy increases the risk of sensitization development in early childhood but not in school-age children. Cumulative allergen exposure from cat ownership and regular cat contact during childhood contribute to sensitization development up to school age.

Clinical implications

Cat allergen avoidance at home alone might be not effective to prevent the development of allergic sensitization in young children.

Section snippets

Study population

The Lifestyle–Immune–System–Allergy (LISA) study is an ongoing birth cohort study of the influences of lifestyle-related factors on the immune system and the development of allergies in childhood. Detailed description of screening and recruitment has been provided elsewhere.18 Briefly, parents of neonates admitted to maternity hospitals in Munich, Leipzig, Wesel, and Bad Honnef, Germany, were contacted. Overall, 3097 neonates were recruited into the study between December 1997 and January 1999.

Results

Dust samples from 2118 parent mattresses and 2098 children mattresses were available. For those children who slept occasionally in their parents' bed or in their own bed, only the mattress the children had very frequent contact with was sampled. The amount of dust and cat allergen load collected from mattresses is listed in Table I. The estimated correlation between cat allergen loads from parent and children mattresses was 0.6. At age 2 and 6 years, 21 (1.3%) and 43 (5.0%) children,

Discussion

Our results showed a positive association between cat allergen exposure during infancy and the sensitization rate up to age 2 years but not at age 6 years. No associations existed between cat allergen exposure in infancy and allergic symptoms and diseases up to age 6 years. Cumulative allergen exposure from cat ownership and regular cat contact outside the domestic area during childhood was found to increase the risk of cat sensitization development at school age. The results also confirmed

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    • Cited by (0)

    Supported by Grant FKZ 20462296 from the Federal Ministry of Environment (BMU) (for Institut für Umweltmedizinische Forschung, Düsseldorf, Germany) and the Federal Ministry for Education, Science, Research, and Technology (No. 01 EG 9705/2 and 01 EG 9732).

    Disclosure of potential conflict of interest: H. Behrendt has received grant support from Bavaria Ministry of Environment. The rest of the authors have declared that they have no conflict of interest.

    ∗

    For a complete list of LISA Study Group members, please contact GSF–National Research Centre for Environment and Health, Institute of Epidemiology.

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    Copyright © 2007 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.