Hypersensitivity Pneumonitis

  • Medical Author:
    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.

  • Medical Editor: Melissa Conrad Stöppler, MD
    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.

What is chronic hypersensitivity pneumonitis?

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

What are the symptoms of chronic hypersensitivity pneumonitis?

Symptoms of chronic hypersensitivity pneumonitis include:

  • Shortness of breath
  • Cough

Chronic disease is believed to occur after prolonged low grade exposure to the offending particles. It is sometimes quite surprising that individuals with a passion for their hobbies or occupation will continue to allow exposure to lung damage (if the offending particles are related to the hobby or job) despite the knowledge that it is harmful.

What are examples of hypersensitivity pneumonitis?

Examples of hypersensitivity pneumonitis include:

  • Farmer's lung disease from exposure to mold spores in hay
  • Pigeon breeder's disease from exposure to protein particles in pigeon droppings
  • Sauna takers' disease from exposure to mold growing in wet containers
  • Mushroom workers' disease from exposure to moldy compost
  • Bagassosis from exposure to moldy sugar cane
  • Winemaker's lung from exposure to a fungus on grapes called Botrytis cinerea
  • An unusual case was published involving a case of hypersensitivity to Canadian goose droppings. The individual was a physician who was exposed to both indoor and outdoor antigens while living in a suburban Illinois community. One can only imagine the tremendous detective work necessary to make this diagnosis.

A more detailed analysis is listed in the table, which includes the types of compounds, bacteria, and molds known to cause hypersensitivity pneumonitis.

Some Types, Antigens and Exposures That Have Been Identified
Disease Name Antigens Exposure
Bagassosis Bacteria (Thermophilic actinomycetes) Moldy bagasse (pressed sugarcane)
Mushroom worker lung Bacteria (Thermophilic actinomycetes) Mushroom compost
Metalworking fluids HP Bacteria (Mycobacterium immunogenum) Mist from metalworking fluids
Hot tub HP Bacteria (Mycobacterium avium complex) Mist from hot tubs
Lifeguard lung Bacteria (Endotoxin) Indoor swimming pool
Farmer's lung Bacteria (Thermophilic actinomycetes)
Fungus (Aspergillus species)
Moldy hay
Humidifer lung Bacteria (T. candidus, Bacillus subtilis, B. cereus, Klebsiella oxytoca)
Fungus (Aureobasidium pullulans)
Amoebae (Naegleria gruberi, Acanthamoeba polyhaga, Acanthamoeba castellani)
Mist from standing water
Compost HP Fungus (Aspergillus) Compost
Malt worker lung Fungus (Aspergillus clavatus) Moldy barley
Peat moss HP Fungi (Monocillium sp, Penicillium citreonigrum) Peat moss
Suberosis Fungus (Penicillum frequentans) Moldy cork dust
Maple bark HP Fungus (Cryptostroma corticale) Moldy wood bark
Wood pulp worker lung Fungus (Alternaria species) Moldy wood pulp
Wood trimmer lung Fungus (Rhizopus species) Moldy wood trimmings
Tree cutter lung Fungi (Penicillium (three species), Paecilomyces sp.,
Aspergillus niger, Aspergillus sp., Rhizopus sp.)
Wood chips from living maple and oak trees
Dry rot HP Fungus (Merulius lacrymans) Moldy rotten wood
Sequoiosis Fungi (Graphium species, Pullularia species) Moldy wood dust
Japanese summer-type HP Fungus (Trichosporon cutaneum) Damp wood and mats
Cheese washer lung Fungus (Pencillum casei or P.roqueforti) Cheese casings
Tobacco worker lung Fungus (Aspergillus sp.) Moldy tobacco
Greenhouse HP Fungi (Aspergillus sp., Penicillium sp., Cryptostroma corticale) Moldy soil
Esparto grass HP Fungus (Aspergillus fumigatus) Moldy esparto used to produce ropes, canvas, sandals, mats, baskets, and paper paste
Soy sauce brewer lung Fungus (Aspergillus oryzae) Fermentation starter for soy sauce
Bird breeder lung Avian proteins Bird droppings and feathers
Mollusc shell HP Aquatic animal proteins Mollusc shell dust
Animal handler lung Animal proteins urine, serum, fur
Wheat weevil HP Wheat weevil (Sitophilus granarius) Infested flour
Silk production HP Silk worm larvae proteins Silk worm larvae
Isocyanate HP TDI, HDI, MDI Paints, resins, polyurethane foams
TMA HP Trimellitic anhydride Plastics, resins, paints
Rose, CS, Lara AR. Hypersenstivity pneumonia In: Mason RJ, Broadus VC, Martin TR, et al. Eds. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa; Saunders Elsevier; 2010; Chap 66.

Medically Reviewed by a Doctor on 3/14/2016

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