Contents
- 1 Hypersensitivity Pneumonitis
- 1.0.1 What are examples of hypersensitivity pneumonitis?
- 1.0.2 What triggers hypersensitivity pneumonitis?
- 1.0.3 What are the symptoms of hypersensitivity pneumonitis?
- 1.0.4 How is hypersensitivity pneumonitis diagnosed?
- 1.0.5 What is the treatment for hypersensitivity pneumonitis?
- 1.0.6 What are complications of hypersensitivity pneumonitis?
Hypersensitivity Pneumonitis
Hypersensitivity pneumonitis (HP) is an inflammation of the lung caused by the body’s immune reaction to airborne particles.
Types of Hypersensitivity Pneumonitis
- Acute Hypersensitivity Pneumonitis: Occurs 4-12 hours after heavy exposure to particles.
- Chronic (long-term) hypersensitivity pneumonitis: Causes lung scarring (fibrosis).
What are examples of hypersensitivity pneumonitis?
Examples include:
- Farmer’s lung disease: Exposure to mold spores in hay.
- Pigeon breeder’s disease: Exposure to protein particles in pigeon droppings.
- Sauna takers’ disease: Exposure to mold growing in wet containers.
- Mushroom workers’ disease: Exposure to moldy compost.
- Bagassosis: Exposure to moldy sugar cane.
- Winemaker’s lung: Exposure to a fungus on grapes called Botrytis cinerea.
- A rare case of hypersensitivity to Canadian goose droppings.
A table lists the types of compounds, bacteria, and molds known to cause hypersensitivity pneumonitis.
| Bacteria (Thermophilic actinomycetes) | Moldy bagasse (pressed sugarcane) |
| Bacteria (Thermophilic actinomycetes) | Mushroom compost |
| Bacteria (Mycobacterium immunogenum) | Mist from metalworking fluids |
| Bacteria (Mycobacterium avium complex) | Mist from hot tubs |
| Bacteria (Endotoxin) | Indoor swimming pool |
| Bacteria (Thermophilic actinomycetes) Fungus (Aspergillus species) |
Moldy hay |
| Bacteria (T. candidus, Bacillus subtilis, B. cereus, Klebsiella oxytoca) Fungus (Aureobasidium pullulans) Amoebae (Naegleria gruberi, Acanthamoeba polyhaga, Acanthamoeba castellani) |
Mist from standing water |
| Fungus (Aspergillus) | Compost |
| Fungus (Aspergillus clavatus) | Moldy barley |
| Fungi (Monocillium sp, Penicillium citreonigrum) | Peat moss |
| Fungus (Penicillum frequentans) | Moldy cork dust |
| Fungus (Cryptostroma corticale) | Moldy wood bark |
| Fungus (Alternaria species) | Moldy wood pulp |
| Fungus (Rhizopus species) | Moldy wood trimmings |
| Fungi (Penicillium (three species), Paecilomyces sp., Aspergillus niger, Aspergillus sp., Rhizopus sp.) |
Wood chips from living maple and oak trees |
| Fungus (Merulius lacrymans) | Moldy rotten wood |
| Fungi (Graphium species, Pullularia species) | Moldy wood dust |
| Fungus (Trichosporon cutaneum) | Damp wood and mats |
| Fungus (Pencillum casei or P.roqueforti) | Cheese casings |
| Fungus (Aspergillus sp.) | Moldy tobacco |
| Fungi (Aspergillus sp., Penicillium sp., Cryptostroma corticale) | Moldy soil |
| Fungus (Aspergillus fumigatus) | Moldy esparto is used to produce ropes, canvas, sandals, mats, baskets, and paper paste |
| Fungus (Aspergillus oryzae) | Fermentation starter for soy sauce |
| Avian proteins | Bird droppings and feathers |
| Aquatic animal proteins | Mollusc shell dust |
| Animal proteins | urine, serum, fur |
| Wheat weevil (Sitophilus granarius) | Infested flour |
| Silkworm larvae proteins | Silkworm larvae |
| TDI, HDI, MDI | Paints, resins, polyurethane foams |
| Trimellitic anhydride | Plastics, resins, paints |
What triggers hypersensitivity pneumonitis?
Particles that trigger hypersensitivity pneumonitis include bacteria, mold, fungi, or inorganic matter.
What are the symptoms of hypersensitivity pneumonitis?
Acute Hypersensitivity Pneumonitis
Symptoms include:
- Fever
- Chills
- Coughing
- Shortness of breath
- Body aches, malaise
Chest X-ray may show small nodules in the lungs. Symptoms usually subside hours to days after exposure. Medical evaluation is necessary to determine treatment.
Chronic Hypersensitivity Pneumonitis
Symptoms include:
Chronic disease occurs after prolonged low-grade exposure to offending particles.
QUESTION
How is hypersensitivity pneumonitis diagnosed?
Many cases are unrecognized. History of repeated episodes of symptoms after exposure is important. Chest X-ray and high-resolution CT scan are used for diagnosis. Lung function tests are performed. Blood antibody and skin tests may be inconclusive. Biopsy may be necessary. Exposure history is crucial for accurate diagnosis.
What is the treatment for hypersensitivity pneumonitis?
Avoiding repeated exposures to the offending particles is crucial. Early diagnosis and prevention lead to a good prognosis.
What are complications of hypersensitivity pneumonitis?
Prolonged exposures can cause permanent lung damage and scarring.
Sources:
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.
Saltoun, et. al. Hypersensitivity pneyonitis resulting from community exposure to Cadada goose droppings when an exteran environmental antigen becomes an indoor environmental antigen. Annals of Allergy, Asthma and Immunology. Vol 84 Issue 1; Pgs 84-86 January 2000.
Takahashi, et. al. Serum Kl-6 Concentrations in Dairy Farmers. Chest. August 2000, vol. 118 no. 2 445-450.
