10 Common Allergy Triggers Slideshow Pictures Take the Quiz on Allergies Allergy Proof Your Home Slideshow

Medical Author:

George Schiffman, MD, FCCP

George Schiffman, MD, FCCP

Dr. Schiffman received his B.S. degree with High Honors in biology from Hobart College in 1976. He then moved to Chicago where he studied biochemistry at the University of Illinois, Chicago Circle. He attended Rush Medical College where he received his M.D. degree in 1982 and was elected to the Alpha Omega Alpha Medical Honor Society. He completed his Internal Medicine internship and residency at the University of California, Irvine.

View Full Profile

Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

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?

Symptoms of acute hypersensitivity pneumonitis include:

• Fever
• Chills
• Coughing
• Shortness of breath
• Body aches, malaise

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.

What is chronic hypersensitivity pneumonitis?

Chronic (long-term) hypersensitivity pneumonitis causes lung scarring (fibrosis).