Background: Patients with chronic bird fancier’s lung
(BFL) can be classified into two types. One group of patients develops
chronic disease with fluctuating acute episodes, including low-grade
fever, mild exertional dyspnea, and cough (fluctuating chronic BFL;
formerly termed recurrent and relapsing chronic BFL). The other group
of patients shows no history of acute episodes (insidious chronic BFL).
The diagnosis of chronic BFL is difficult, since the onset of chronic
BFL may be insidious, with few if any symptoms during the early stages
of the disease process.
Study objective: To attempt to
diagnose the conditions of these patients more precisely, inhalation
provocation tests were conducted using avian dropping extracts.
Design: Retrospective chart review.
Setting: The Tokyo Medical and Dental University Hospital
Patients: Eleven patients with chronic BFL
(6 with fluctuating chronic BFL and 5 with insidious chronic BFL) and 6
control subjects (4 asymptomatic bird owners and 2 idiopathic pulmonary
fibrosis patients) were evaluated.
results: Inhalation provocation tests using avian dropping
extracts were conducted. All BFL patients were evaluated as positive or
probable by inhalation challenge, whereas control subjects were
evaluated as negative. A peripheral leukocytosis, an increase of
alveolar-arterial oxygen pressure difference, an increase of body
temperature, and the development of respiratory symptoms including
cough and dyspnea were more frequently observed in chronic BFL patients
than in control subjects. All the BFL patients had an increase in
neutrophils in BAL fluids following inhalation challenge.
Conclusions: We validated the utility of inhalation
challenge for the diagnosis of chronic BFL, including fluctuating and
insidious BFL. We also demonstrated that neutrophilia in BAL fluids
following inhalation challenge could be added to the diagnostic
criteria for chronic BFL.