Hypersensitivity Pneumonitis

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What is hypersensitivity pneumonitis and what are its causes?

Hypersensitivity pneumonitis (HP) is an inflammation of the lung (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 matter.

What is acute hypersensitivity pneumonitis?

Acute hypersensitivity pneumonitis tends to occur 4-12 hours after exposure (usually heavy exposure) to the particles.

What are the symptoms of acute hypersensitivity pneumonitis?

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Symptoms of acute hypersensitivity pneumonitis include:

Chest X-ray may show diffuse small nodules in the lungs. Typically, the symptoms will subside hours to days after exposure (provided there are no repeated exposures). The abnormalities on chest X-ray abnormalities will also disappear. The patient's condition can deteriorate after exposure; therefore it is imperative that a medical evaluation be performed to determine the best course of treatment.

Medically Reviewed by a Doctor on 10/16/2014

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