A form of alveolitis or pneumonitis due to an acquired hypersensitivity to inhaled antigens associated with farm environment. Antigens in the farm dust are commonly from bacteria actinomycetes (SACCHAROPOLYSPORA and THERMOACTINOMYCES), fungi, and animal proteins in the soil, straw, crops, pelts, serum, and excreta.

Hypersensitivity pneumonitis caused by the repeated exposure and inhalation of biological dust (such as hay dust, mold spores, or other agricultural products). It is considered a type II hypersensitivity inflammatory reaction. In the acute phase, signs and symptoms include fever, chills, cough, dyspnea, headache, and chest tightness. The subacute phase manifests as chronic cough, dyspnea, anorexia, and weight loss. The chronic phase results from the prolonged exposure to the antigen and is characterized by severe dyspnea and irreversible damage to the lungs.

Systemic and pulmonary reactions resulting from inhalation of dust from moldy hay, threshing dust, or moldy straw, by persons who have become hypersensitive to antigens in the dust; most often associated with inhalation of spores of Micromonospora faeni or Thermoactinomyces vulgaris.

Farmer's lung is a type of hypersensitivity pneumonitis. Hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis, is an immunologically mediated inflammatory disease of the lung involving the terminal airways.

Farmer's lung, a pulmonary disorder that results from the development of hypersensitivity to inhaled dust from moldy hay or other fodder. In the acute form, symptoms include a sudden onset of breathlessness, fever, a rapid heartbeat, cough (especially in the morning), copious production of phlegm...