Ans: (c) X-ray features upper lobe predominant in chronic HPRef: Fishman's Pulmonary Disease and Disorders, 5th edition, Chapter 58Farmer's LungResults from exposure to moldy hay containing spores of Thermophilic Actinomycetes that produce a hypersensitivity pneumonitisMost cases of farmer's lung disease occur in cold, damp climates in late winter and early spring, when farmers (usually male) use stored hay to feed their livestockManifestations of the disease may be acute, subacute or chronicAcute clinical presentation includes transient fever, hypoxemia, myalgias, arthralgias, dyspnea, and cough that occur 2 to 9 hours after exposure and resolve in 12 to 72 hours without specific treatmentIn acute HP, chest radiographs-diffuse poorly defined nodular radiodensities, often with areas of ground-glass radiodensities or occasionally even consolidation, tend to occur in the lower lobes and spare the apicesChronic form is clinically more insidious, and patients may lack a history of acute episodes, but present with a gradual onset of cough, dyspnea, fatigue, and weight loss. Symptoms are usually present for months to years.In chronic HP, chest radiographs - diffuse linear and nodular radiodensities, with sparing of the bases and upper-lobe predominance, and volume loss. Pleural effusions and thickening are very unusual