Which is best for diagnosis of Hypersensitivity pneumonitis?: (A) Chest imaging, (B) Pulmonary function testing, (C) Serum precipitins, (D) Clinical prediction rule
Answer is D. Hypersensitivity pneumonitis: Type IV HSR Chest Imaging - normal in Hypersensitivity pneumonitis Pulmonary function testing - Obstructive pattern Clinical prediction rule- eg Farmer's Lung Exposure to antigen Presence of precipitin Recurrence of symptoms >4-6 hrs Crackles on auscultation Weight loss Farmer lung:- Thermophilus actinomyces