title: Etiologic role of unapparent exposure in cat allergy.
abstract: To determine the importance of unnoticed exposure to cat, we studied 20 patients with a history of respiratory allergy. All the patients had a positive prick test to cat dander extract, and none of them kept cats as pets. The prick test was carried out with a dander extract from cat at a concentration of 100 BU/ml. The specific IgE was determined by the commercially available Pharmacia CAP System. We carried out a conjunctival challenge test. The concentration of Fel d 1 was quantified in dust samples from the patients' homes by a commercially available method. The patients were reassessed in order to establish a relation between exposure and symptoms, and concealed allergen sources. Sixteen patients showed significant levels of Fel d 1 in their homes (mean of 3.35 micrograms/g of dust). The conjunctival challenge test was positive in 15 patients. These patients showed an exposure mean of 0.4 microgram/g of dust. The mean levels of specific serum IgE were higher in those patients with a positive challenge than in those with a negative challenge (P = 0.0145). In nine reassessed patients, a relation was established between natural exposure and the onset of the symptoms. A possible hidden allergen source was established in 11 patients.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Unidad de Alergia, Hospital Clinic Universitari, Valencia, Spain.
authors.forename: J V
authors.initials: JV
authors.lastname: Brasó-Aznar
authors.forename: A
authors.initials: A
authors.lastname: Pelaez-Hernandez
authors.forename: A
authors.initials: A
authors.lastname: Rochina-Puchades
authors.forename: C
authors.initials: C
authors.lastname: Morales-Rubio
authors.forename: E
authors.initials: E
authors.lastname: Burches Baixauli
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D002415:Cats / Q000276:immunology*; D004391:Dust; D004781:Environmental Exposure; D000939:Epitopes; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology* / Q000503:physiopathology; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology; D008297:Male; D008875:Middle Aged
chemical_list: D000485:Allergens; D004391:Dust; D000939:Epitopes; D006023:Glycoproteins; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus