It is appropriate to refer a patient with suspected hypersensitivity pneumonitis to a respiratory specialist for further evaluation when there is diagnostic uncertainty, when interstitial lung disease is suspected, or when initial investigations such as chest X-ray and lung function tests suggest an interstitial lung process.
Referral should be considered to enable specialist assessment including detailed history, clinical examination, lung function testing, and high-resolution CT thorax, as well as multidisciplinary team evaluation if needed.
Specialist referral is also indicated if the diagnosis is unclear after initial assessment or if invasive diagnostic procedures such as bronchoalveolar lavage, transbronchial biopsy, or surgical lung biopsy are being considered to confirm the diagnosis.
Early referral is important to identify and manage environmental or occupational exposures causing hypersensitivity pneumonitis and to prevent progression of lung damage.
In summary, refer patients with suspected hypersensitivity pneumonitis to a respiratory specialist when there is diagnostic uncertainty, evidence of interstitial lung disease, or need for advanced diagnostic procedures and multidisciplinary assessment.
References: NICE CG163, NICE CKS