Diagnosis and Evaluation of Hypersensitivity Pneumonitis (HP)

Publication Date: April 13, 2021
Last Updated: March 14, 2022

Recommendations

1. In patients with suspected hypersensitivity pneumonitis (HP), we suggest gathering a thorough clinical history of exposures focused on establishing the type, extent, and temporal relationship of exposure(s) to symptoms. (GPR, )
658
2. In patients with suspected HP, if the inciting antigen (IA) is thought to be related to an occupational exposure, we suggest considering the inclusion of an occupational medicine specialist and an environmental hygienist during the multidisciplinary diagnostic workup, especially when the source of exposure is obscure or unverified. (GPR, )
658
3. In patients with suspected HP, we suggest classifying patients based on the likelihood of an occupational or environmental inciting antigen exposure. (W - Weak, VL - Very Low)
658
4. For patients with either newly diagnosed or a working diagnosis of HP, we suggest classifying the disease as fibrotic or nonfibrotic based on the presence or absence of fibrosis on high-resolution CT (HRCT) of the chest. (W - Weak, VL - Very Low)
658
5. In patients with suspected HP, if an IA exposure is identified and then completely avoided, we suggest using clinical improvement with antigen avoidance to support the diagnosis of HP, but not relying solely on the lack of clinical improvement with antigen avoidance to rule out the diagnosis of HP. (W - Weak, VL - Very Low)
658
6. For patients with suspected HP, we suggest not relying solely on clinical improvement with medical therapy to confirm a diagnosis of HP or on the lack of clinical improvement with medical therapy alone to rule out the diagnosis of HP. (W - Weak, VL - Very Low)
658
7. For patients with suspected HP, we suggest not relying solely on serum antigen-specific immunoglobulin G (IgG) or immunoglobulin A (IgA) testing to confirm or rule out the diagnosis of HP. (W - Weak, VL - Very Low)
658
8. For patients with suspected HP, we suggest not performing antigen-specific inhalation challenge testing to support the diagnosis of HP. (W - Weak, VL - Very Low)
658
9. For patients with suspected HP, we suggest not performing antigen-specific lymphocyte proliferation testing to support the diagnosis of HP. (W - Weak, VL - Very Low)
658
10. For patients with suspected HP, we suggest the integration of HRCT findings characteristic of HP with clinical findings to support the diagnosis of HP, but not using the CT findings in isolation to make a definite diagnosis. (W - Weak, VL - Very Low)
658
11. For patients with suspected HP, we suggest using a multidisciplinary discussion (MDD) for diagnostic decision-making. (W - Weak, VL - Very Low)
658
12. For patients with suspected HP who have a compelling exposure history within the appropriate clinical context and a chest HRCT pattern typical for HP, we suggest not routinely using BAL fluid analysis to confirm a diagnosis of HP. (W - Weak, VL - Very Low)
658
13. In patients with suspected HP, we suggest considering histological lung biopsy for additional diagnostic evaluation when all available data such as clinical, laboratory, and radiologic findings along with bronchoscopic results do not yield a confident diagnosis and results may help guide management. (W - Weak, VL - Very Low)
658
14. For patients with suspected HP, we suggest integrating biopsy findings with clinical and radiological findings to support the diagnosis of HP in the context of the MDD. (W - Weak, VL - Very Low)
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Recommendation Grading

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Overview

Title

Diagnosis and Evaluation of Hypersensitivity Pneumonitis (HP)

Authoring Organization

Publication Month/Year

April 13, 2021

Last Updated Month/Year

July 12, 2023

Supplemental Implementation Tools

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Inclusion Criteria

Female, Male, Adult, Older adult

Health Care Settings

Ambulatory, Hospital

Intended Users

Physician, nurse practitioner, nurse, physician assistant

Scope

Assessment and screening, Diagnosis

Diseases/Conditions (MeSH)

D006967 - Hypersensitivity

Keywords

interstitial lung disease, evidence-based medicine, Guidelines, hypersensitivity pneumonitis

Source Citation

Fernández Pérez ER, Travis WD, Lynch DA, Brown KK, Johannson KA, Selman M, Ryu JH, Wells AU, Tony Huang YC, Pereira CAC, Scholand MB, Villar A, Inase N, Evans RB, Mette SA, Frazer-Green L. Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report. Chest. 2021 Aug;160(2):e97-e156. doi: 10.1016/j.chest.2021.03.066. Epub 2021 Apr 20. PMID: 33861992.

Supplemental Methodology Resources

Data Supplement

Methodology

Number of Source Documents
230
Literature Search Start Date
March 1, 2018
Literature Search End Date
May 1, 2020