3.1 Clinical feature
Clinical data were obtained from patients’ records and have been reported in Table 1. The mean age was 55.2 (26-83) years for the 31 FDL patients (16 women and 15 men) and 64.6 (46-82) years for the 15 BFL patients (10 women, 5 men). Thirty-three per cent of FDL patients were non-smokers compared to 73% for BFL patients. The antigenic source was a feather duvet for eighteen patients, a feather pillow for five and a combination of both in eight. Over sixty-six percent of BFL patients were exposed to pigeons, and only 20% were exposed to more than one species of bird. No FDL patients were exposed to birds and no BFL patients were exposed to bedding feathers. Of the patients with FDL, 64.5% had a chronic course of HP against 40% for BFL patients. Cough and dyspnea were the predominant symptoms in the two groups of patients. BAL was performed for 28/31 (90%) patients with FDL and 12/15 (80%) of BFL patients. A BAL lymphocyte count of at least 20% were found in 13/28 (46%) patients FDL and in 12/12 (100%) of BFL patients.