Hypersensitivity
Pneumonitis: Common Features
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Symptoms: presents
acutely, as flu-like illness with cough; subacutely, as recurrent
"pneumonia"; and chronically, as exertional dyspnea, productive cough
and weight loss;
Signs:
abnormal chest
x-ray in most patients; crepitant rales in some cases; specific
precipitating antibodies in some cases; pulmonary function tests show
a restrictive defect in early disease and a restrictive, obstructive
or mixed defect in late disease;
Latency: few weeks to
years;
Onset of symptoms
after exposure: 4 to 12 hours;
Repeated exposure to:
1) bioaerosols of microbial or animal antigens; or 2) a few reactive
chemicals;
Resolution:
improvement or complete recovery if exposure terminated early;
otherwise, may progress to interstitial fibrosis;
Comments: In the acute
form, symptoms may resolve within a few days following the exposure.
Note: A bioaerosol is a suspension of
particles of biologic origin in a gas; it can be a mist or a dust.
Some of the Types, Antigens and
Exposures that Have Been Identified
DISEASE NAME |
ANTIGENS |
EXPOSURE |
Farmer's lung |
Thermophilic actinomycetes
Fungus (Aspergillus
species) |
Moldy hay |
Bagassosis |
Thermophilic
actinomycetes |
Moldy bagasse (pressed
sugarcane) |
Malt worker's lung |
Fungus (Aspergillus
clavatus) |
Moldy barley |
Humidifier lung |
Bacteria (T.
candidus, Bacillus subtilis, B. cereus, Klebsiella oxytoca)
Fungus (Aureobasidium
pullulans )
Amoebae (Naegleria gruberi,
Acanthamoeba polyhaga, Acanthamoeba castellani) |
Mists from standing
water |
Mushroom worker's lung |
Thermophilic
actinomycetes |
Mushroom compost
|
Compost lung |
Fungus (Aspergillus) |
Compost |
Suberosis |
Fungus (Penicillum
frequentans) |
Moldy cork dust |
Maple bark-stripper's
lung |
Fungus (Cryptostroma
corticale) |
Moldy wood bark |
Wood pulp worker's
lung |
Fungus (Alternaria
species) |
Moldy wood pulp |
Wood trimmer's disease |
Fungus (Rhizopus
species) |
Moldy wood trimmings |
Sequoiosis |
Fungi (Graphium
species, Pullularia species) |
Moldy wood dust |
Japanese summer-type
HP |
Fungus (Trichosporon
cutaneum) |
Damp wood and mats |
Cheese-washer's lung |
Fungus (Pencillum
casei or P.roqueforti) |
Cheese casings |
Metalworking fluids HP |
Mycobacteria chelonae;
fungi |
Microbially
contaminated, water-based MWFs |
Bird-breeder's lung |
Avian proteins |
Bird droppings and
feathers |
Mollusc shell HP |
Aquatic animal
proteins |
Mollusc shell dust |
Isocyanate HP |
TDI, HDI, MDI
|
Paints, resins,
polyurethane foams |
TMA HP |
Trimellitic anhydride |
Plastics, resins,
paints |
References:
"Hypersensitivity Pneumonitis" by Cecile Rose in (Harber),
"Hypersensitivity Pneumonitis" by Yvon Cormier in (Rom),
"Occupational Lung Diseases" by John Balmes and Cornelius Scannell in
(LaDou),
and Occupational Exposure to
Metalworking Fluids, NIOSH, (http://www.cdc.gov/niosh/metalw.html).
Revised
August 05, 2005
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