Diagnosis of Hypersensitivity Pneumonitis in Adults - Clinical Practice Guideline
The American Thoracic Society offers official clinical practice guidelines for the diagnosis of hypersensitivity pneumonitis (HP) in adults.
In this document, a review committee considered six questions from which recommendations were formulated by a multidisciplinary committee of experts in the field using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.
The recommendations include, but are not limited to:
HP must be considered in the differential diagnosis for patients with newly identified interstitial lung disease (ILD).
HP can be categorized into two clinical phenotypes - nonfibrotic HP and fibrotic HP - with separate recommendations made for each type.
For both types, the following recommendations are made:
A thorough history should be taken to identify potential environmental causes associated with HP.
Serum IgG testing targeting potential antigens association with HP is suggested.
Bronchoalveolar lavage (BAL) fluid can be obtained and analysed for lymphocytes.
Surgical lung biopsy is suggested only when all other diagnostic testing has failed.
For nonfibrotic HP, transbronchial forceps lung biopsy is also suggested.
For fibrotic HP, transbronchial lung cryobiopsy is also suggested.