RESUMO
The purpose was to study the distribution of clinical expression of asthma in asthmatic families regarding age at asthma onset, duration of disease, skin prick test, serum total IgE, FEV1, therapeutic management and inheritance to find markers of severity of the disease. Sixty-eight subjects from 11 families were selected; 28 asthmatic patients were eligible to participate in the study, since they belonged at least to two family generations. Forty nonasthmatic relatives were also included. The asthmatics were submitted to a clinical questionnaire, physical examination, pre- and postbronchodilator spirometry, bronchial hiperesponsiveness test to histamine, skin prick test, and total serum IgE analysis. Asthma severity classification was: 11 mild (39 percent), 8 moderate (29 percent), and 9 severe (32 percent). Only two of seven markers of the disease were associated with asthma severity (p<0.05). Asthma severity was significantly associated with correct or incorrect treatment (p=0.004). The patients who correctly followed treatment had less severe disease than those patients who followed it incorrectly. Also, asthma severity was significantly associated with the degree of obstruction measured by FEVi (p=0.02). There is no significant association with the other tested markers. We conclude that asthma severity was highly related to poor or no effective treatment, such as no regular anti-inflammatory medication intake, frequent exposure to common indoor and outdoor triggers and difficuity in recognizing early warning signs as well as the degree of obstruction.