P. Plaschke C. Janson B. Balder O. Lo È whagen B. Ja È rvholm Authors' affiliations: P. Plaschke, Roskilde County Hospital, Denmark, and Allergy Research Centre, Sahlgrenska University Hospital, Go È teborg, Sweden C. Janson, Department of Lung Medicine and Asthma Research Centre, Akademiska sjukhuset, Uppsala, Sweden B. Balder, O. Lo È whagen, Allergy Research Centre, Sahlgrenska University Hospital, Go È teborg, Sweden B. Ja È rvholm, Department of Occupational and Environmental Medicine, Umea Ê University, Umea Ê , Sweden Correspondence to: Dr P. Plaschke Department of Medicine Roskilde Amts Hospital Kùgevej 7-13 DK - 4000 Roskilde Denmark Date: Accepted for publication 18 February 1999 To cite this article: Plaschke P., Janson C., Balder B., Lo È whagen O. & Ja È rvholm B. Adult asthmatics sensitized to cats and dogs: symptoms, severity, and bronchial hyperresponsiveness in patients with furred animals at home and patients without these animals. Allergy 1999, 54, 843±850. Copyright # Munksgaard 1999 ISSN 0105-4538 Original article Adult asthmatics sensitized to cats and dogs: symptoms, severity, and bronchial hyperresponsiveness in patients with furred animals at home and patients without these animals A reduction of exposure to allergens should be an obvious cornerstone in the treatment of allergic diseases such as atopic asthma and allergic rhinitis (1, 2), but there are few studies of the importance of such reductions. Cats and dogs are important sensitizers in patients visiting emergency Key words: allergy avoidance; asthma; bronchial hyperresponsiveness; cats; dogs; eosinophils; indoor allergens; peak-flow variability. Background: Domestic furred animals are important sources of allergens in asthma, but few clinical studies have investigated the effects of exposure to or elimination of these allergens. The objective of this study was to investigate whether pet-sensitized asthmatics with pets at home have worsened asthma, compared with similar asthmatics without pets. Methods: In a cross-sectional epidemiologic study, 129 adult asthmatics sensitized to cats or dogs were investigated by interviews, skin prick tests, specific IgE, eosinophil counts, and bronchial methacholine challenge tests. Patients with a cat or dog at home (n=39) were compared with subjects without pets (n=90). Results: More subjects with pets had symptoms, inhaled or oral steroids, abnormal peak-flow records, higher eosinophil counts, and a higher degree of bronchial hyperresponsiveness than subjects without pets. Asthmatics with pets more frequently ascribed their symptoms to their home environment, but fewer of them reported that their symptoms were elicited by contact with cats or dogs. Conclusions: This study strongly indicates that living with a cat or a dog aggravates symptoms and biomarkers of airway inflammation in asthmatics sensitized to cats or dogs. The study indicates that avoidance of these allergens may be an important measure in the treatment of sensitized asthmatics. 843