How should I approach the management of a patient with hypersensitivity pneumonitis who continues to be exposed to the offending antigen?

Management of a patient with hypersensitivity pneumonitis (HP) who continues to be exposed to the offending antigen should prioritise immediate and complete avoidance of the antigen to prevent ongoing lung injury and progression to fibrosis. Continued exposure despite symptoms typically leads to worsening inflammation and irreversible lung damage, so identifying and eliminating the source is critical ⁴.

If antigen avoidance is not feasible or incomplete, corticosteroid therapy may be considered to reduce inflammation and improve symptoms, but this is generally an adjunct rather than a substitute for antigen removal ⁴.

Supportive care including monitoring lung function and symptoms is essential, and patients should be counselled on the risks of ongoing exposure. In some cases, occupational health referral and environmental assessment may be necessary to facilitate antigen avoidance ⁴.

Recent literature emphasises that persistent antigen exposure is the main driver of disease progression in HP, reinforcing the guideline recommendation that antigen avoidance is the cornerstone of management (Patel et al., 2001). Corticosteroids can provide symptomatic relief but do not prevent fibrosis if exposure continues (Patel et al., 2001).