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Original Article


Thirty cases of bronchial asthma associated with exposure to pet hamsters


T. Niitsuma, A. Tsuji, M. Nukaga, A. Izawa, M. Okita, N. Maruoka, A. Oguchi, S. Morita, Y. Matsumura, M. Tsuyuguchi, T. Hayashi

Third Department of Internal Medicine, Tokyo Medical University, Shinjuku, Tokyo 160-0023, Japan

J Invest Allergol Clin Immunol 2004; Vol. 14(3): 221-224



Background: The identification, isolation, and elimination of allergen(s) causing bronchial asthma are the most efficient form of treatment. The pet industry has diversified recently, increasing the risk of exposure of pet owners to many unknown antigens. We clinically studied the characteristics of asthma associated with exposure to pet hamsters.

The study group comprised 30 adults in whom the onset, recurrence, or exacerbation of asthma was triggered by contact with pet hamsters. Clinical characteristics such as sex, age, period required for symptom onset, species of hamster, treatment and disease course, smoking status, and hamster-specific IgE antibodies in serum were studied.

Results: The male: female ratio of the study group was 1:1.3, and mean age was 37.7 years. Patients with no previous history of asthma initially presented with cough, progressing to episodes of asthma. Asthmatic symptoms were associated with hamster contact and ranged in severity from mild to severe. Three patients required hospital
admission for treatment. The mean period from the start of hamster exposure to the onset of asthmatic episodes was 15.7 months. Dwarf hamsters were responsible for most cases. The CAP-RAST score for hamster-specific IgE antibodies was 1 to 4 in 22 patients and 0 in 8 patients. Eight patients with a score of 1 or higher for hamsterspecific
IgE antibodies had a CAP-RAST score of 0 for mite antigen. In these patients, terminating hamster contact resulted in a rapid improvement in symptoms, with no need for further treatment. Twenty-three of the 30 subjects (76.7%) were smokers.

Conclusion: Exposure to pet hamsters is an important risk factor for the onset, recurrence, or exacerbation of asthma. Smoking may also increase the risk of asthmatic symptoms in patients exposed to hamsters.

Key words
: bronchial asthma, pet allergy, hamster