24
Diagnosis
Figure 7. Diagnostic Evaluation of Possible Hypersensitivity
Pneumonitis (HP)
Exposure identified AND typical HP pattern on
HRCT AND BAL lymphocytosis
High confidence diagnosis of HP
Multidisciplinary discussion
Exposure assessment
a
and chest
HRCT scan
b
BAL with lymphocyte cellular analysis,
with or without TBLB
c
a
Exposure assessment includes a thorough clinical history and/or
serum IgG testing against potential antigens associated with HP
and/or, in centers with the appropriate expertise and experience,
specific inhalational challenge testing.
b
High-resolution computed tomography should be performed
using the technique described in Table 2 and then reviewed with a
thoracic radiologist.
c
Transbronchial lung biopsy is suggested for patients with potential
nonfibrotic HP (see question 4, recommendation 1). #TBLC is
suggested for patients with potential nonfibrotic HP, depending
on local expertise (see question 5, recommendation 2). ##SLB is
infrequently considered in patients with nonfibrotic HP.
