ASSOCIATION OF ASTHMA WITH SERUM IGE AND SKIN-TEST REACTIVITY TO ALLERGENS AMONG CHILDREN LIVING AT HIGH-ALTITUDE - TICKLING THE DRAGONS BREATH

Asthma in children and young adults is strongly associated with immedi ate hyersensitivity to indoor allergens, notably those derived from th e house dust mite. In addition, outdoor air pollution is considered to aggravate existing asthma. We investigated the prevalence of asthma a nd the pattern of allergen sensitization in a mite-free environment wi th low levels of outdoor air pollution. A total of 567 children aged b etween 12 and 14 attending Los Alamos Middle School, NM (altitude 7,20 0 feet) were screened using a respiratory questionnaire; 120 children (53 control children) underwent allergen skin testing and serum IgE me asurement, and their bronchial reactivity to histamine was measured. D ust was collected from 111 homes and the level of indoor mite and cat allergen measured. The prevalence of respiratory symptoms was high (13 %), and from the detailed testing it was estimated that 6.3% of the ch ildren had asthma (defined as symptomatic bronchial reactivity). Child ren with asthma had elevated IgE, 367 (179 to 755) versus 38 (23 to 61 ), and predominant sensitization to cat, 68 versus 20% (p < 0.001). A high number of households (77%) had a pet cat or dog. The concentratio n of mite allergen was very low (mean 0.18 mu g Der p I/g sieved house dust), whereas that of cat allergen was high in homes with a cat (80. 8 mu g Fel d I/g) but also in homes with no cat (3.2 mu g Fel d I/g). The results show that in a mite-free environment with low levels of ou tdoor air pollution, asthma was still a major cause of morbidity among schoolchildren. Asthma was strongly associated with elevated IgE and sensitization to other indoor allergens, notably those derived from ca t.