Hypersensitivity pneumonitis is usually an occupational disease in which exposure to organic dusts, fungus, or molds leads to acute lung disease. It is also called farmer’s lung, mushroom picker’s disease, humidifier or air-conditioner lung, and bird breeder’s lung. Over time, this acute condition may turn into chronic lung disease.

What is hypersensitivity pneumonitis?
Hypersensitivity pneumonitis is an inflammation of the lungs (usually of the very small airways) caused by the body’s immune reaction to small air-borne particles. These particles can be bacteria, mold, fungi, or even inorganic.

Causes
The most common cause is exposure to organic dusts, fungus, or mold. Sometimes exposure occurs in the home from fungus present in humidifiers, heating systems, and air conditioners. Some hobbies, such as owning birds, can lead to exposure.

Symptoms
Cough, fever, chills, shortness of breath, weight loss, and feeling ill.

Treatment
The goal of treatment is to identify what the patient was exposed to and avoid further exposure to it. Many times a change of occupation is necessary if the allergen can not be avoided. If exposure continues it is possible to have permanent lung damage and scarring.
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