Mite allergen exposure is a risk for the incidence of specific sensitization,☆☆,,★★

https://doi.org/10.1016/0091-6749(94)90070-1Get rights and content

Abstract

Background: Mite allergen exposure is essential for the process of specific allergic sensitization. However, it is not clear whether incidence of specific sensitization at school age depends on the level of mite antigen exposure. Therefore the relationship between mite allergen exposure and incidence of specific sensitization was investigated. Methods: Eighteen hundred twelve primary school children were enrolled in a population-based 2-year follow-up study. In three consecutive skin prick tests (SPTs), each 12 months apart, sensitization to Dermatophagoides pteronyssinus (Dpt) and six non-Dpt allergens was ascertained. To assess exposure to Der p I between the first and second SPTs (period I) and the second and third SPTs (period II), the amount of antigen per gram of dust (taken from the children's mattresses was measured. By using the SPT reactions to Dpt as a basis, conversions after “no wheal” were classified as doubtful incidence (average yearly incidence = 6.7%) or definite incidence (average yearly incidence = 3.2%). Then, with the use of multiple logistic regression, the risk of exposure to Der p I (medians: 1.4 μg/gm in period I, 1.6 μg/gm in period II) was analyzed with adjustment being made for gender, low gestational age, parental atopy, and initial sensitization to non-Dpt allergens. Results: Regarding doubtful incidence, the analysis failed to identify a reliable cutoff point of exposure. For definite incidence, the Der p I exposure represents a significant risk in the total population, starting from a concentration of 9 μg/gm. This effect is modified by an initial sensitization to non-Dpt allergens: for these children exposure to concentrations above 2 μg/gm poses a significant risk, whereas for the population without other initial sensitizations, only an extremely high cutoff limit (>80 μg/gm) gains significance. Conclusion: Our data suggest that a concentration limit of 2 μg Der p I antigen per gram of dust should be regarded as minimal avoidance level for primary prevention in children with sensitization to other inhalant allergens. (J ALLERGY CLIN IMMUNOL 1994;94:44-52.)

Section snippets

METHODS

Data were collected in a longitudinal study designed to assess risk factors for allergy and asthma in children. To obtain a population-based sample of elementary school children, all parents whose children started school in 1989 were invited to participate. Questionnaires were distributed to 2604 families and were returned by 1812 families (70%). Data from the first cross section are presented in detail elsewhere.7 Three consecutive skin prick tests (SPTs), each 12 months apart, were carried

RESULTS

In the course of the 2-year follow-up study, the number of participants decreased from 1812 (initial age: mean, 7.3 years; standard deviation, 0.4 years) to 1392 (data with regard to the incidence of sensitization). However, the distribution of relevant variables did not change (Table I).

The changes (transitions) regarding sensitization to Dpt between SPT 1 and SPT 2 (period I) and between SPT 2 and SPT 3 (period II) are presented in Fig. 1. During period I, among 1034 individuals with

DISCUSSION

The objective of this study was to investigate the effect of dust mite allergen exposure on the incidence of sensitization to Dpt. For this purpose, the Der p I concentration in a dust sample from each child's mattress, which has been shown to be the best indicator of mite infestation, was measured.13 Dust sampling was carried out in the same season, providing similar distribution patterns for the months in which the samples were taken. This aspect is of importance because natural variation and

Acknowledgements

We thank Mrs. Susanne Huber, Mrs. Monika Mortensen, and Mrs. Sabine Linser-Haar for their excellent collaboration in the field study; they conducted the SPTs, the household visits, and the analyses in the laboratory, respectively.

References (18)

There are more references available in the full text version of this article.

Cited by (226)

  • Indoor Environmental Exposures and Their Relationship to Allergic Diseases

    2023, Journal of Allergy and Clinical Immunology: In Practice
View all citing articles on Scopus

From aUniversity Children’s Hospital, Freiburg; b University Children’s Hospital, Vienna; and c NORDIG Institute for Health Research and Prevention, Hamburg.

☆☆

Supported by the German Federal Ministry for Research and Technology (grant no. 0701565).

Reprint requests: Joachim Kuehr, MD, University Children’s Hospital, D-79106 Freiburg, Mathildenstr. 1, Germany.

★★

0091-6749/94 $3.00 + 01/1/54748

View full text