The medical term extrinsic allergic alveolitis (also known as hypersensitivity pneumonitis) is used to refer to a family of lung diseases that are characterized by a patient’s lungs become inflamed due to an allergic reaction which often results from exposure to triggers like specks of dust of vegetable and animal origin.
Obviously, the name “extrinsic allergic alveolitis”, is a seemingly complicated one, it accurately describes the origin, as well as the nature of this family of diseases.
“extrinsic”– This means the cause originates from outside the body.
“allergic”– This means the condition is caused by the allergic reaction of the patient’s body to a particular substance or health condition.
“alveolitis”– This refers to an inflammation in the inner parts of the patient’s lungs (alveoli is the name for the small air sacs found in the lungs).
What causes allergic alveolitis?
It has been discovered that Intense or prolonged exposure to vegetable or animal dust can lead to allergic alveolitis. These harmful dust particles should be about 5 microns or smaller for them to get into the alveoli successfully.
Vegetable and Animal specks of dust are a complex mixture that originates from a large number of varying sources such as wood, bark, husks, animal dander, and even microorganisms which includes bacteria and fungi.
The microorganisms function to produce toxic chemicals which become a part of the harmful mixture. Traces of bird droppings, tiny insects and insect fragments, and dried urine of rats can also be found in the dust. Other sources of dust include Mouldy hay, grain straw, and feathers.
How does allergic alveolitis?
Allergic alveolitis is not a condition that develops on the very first day a person is exposed to vegetable or animal dust. This means there has to be a prolonged and repeated exposure to these triggers for the condition to develop.
Even with constant exposure, not every worker in professions that are susceptible to the triggers, will develop an allergic reaction to vegetable or animal dust. About ten to forty percent of individuals exposed to these specks of dust do not show any allergic symptoms.
What could possibly trigger the allergy? triggers to this allergy are usually caused by a complicated reaction of a person’s body’s natural defense system which is designed to naturally protect the lungs from harmful external substances.
In some people, the chemical reaction of the body’s defense system that should ordinarily be a protector to the lungs will cause the inflammation and ultimately, lung damage. There is a changing response of the body to the presence of dust in a person’s lungs, this response is called sensitization.
What are the symptoms of allergic alveolitis?
Hypersensitivity pneumonitis or allergic alveolitis, once an individual becomes sensitized, can reveal three varying types of responses: the acute (intense) response, the sub-acute (recurrent) response, and the chronic (long-term) response. Also, note that the signs and symptoms of allergic alveolitis will vary between people.
The acute attack response usually starts with heavy exposure to a trigger. This response starts with a fever, some muscular aches and also a general, malaise or unwell feeling.
The above symptoms are often accompanied by tightness in the patient’s chest, shortness of breath, and a dry cough. Symptoms may show up between 4 and 8 hours after a person has been exposed to triggers.
The sub-acute response most frequently occurs in people who are exposed to a relatively low level of vegetable or animal dust. This response is marked by cough, shortness of breath, chronic bronchitis, or anorexia or weight loss.
The chronic response is one that develops after a persistent acute attack as well as a recurrent sub-acute response. It is also marked by increasing cough, shortness of breath, chronic bronchitis, lung fibrosis, and anorexia or weight loss. The bad news here is that a victim permanently suffers lung damage.
How is allergic alveolitis recognized and treated?
In terms of diagnosis, the most trusted evidence for allergic alveolitis or hypersensitivity pneumonitis is the person’s occupation and his or her history of exposure to vegetable or animal dust.
Although it is not strange for the doctor to want to run a few tests, like blood tests or lung function tests, lung x-rays, these are not specific. Also, these tests may not distinguish between extrinsic allergic alveolitis/hypersensitivity pneumonitis, and/or other lung problems.
Following diagnosis, a patient must avoid any future exposure to vegetable or animal dust. By avoiding any further exposure, the patient should experience significant improvement.
Nevertheless, for serious cases of allergic alveolitis, patients need to take medications that make breathing easier.
What occupations are at risk of exposure to allergic alveolitis?
Hypersensitivity pneumonitis or allergic alveolitis occurs in many, different occupations. So numerous that the list provided below is not complete.
The following lists several some examples and the occupations that are related.
1. Disease: Air conditioner/humidifier lung
Exposure: Humidifier water
Preventive maintenance: Maintenance of air and water handling systems.
2. Disease: Animal handlers’ lung
Exposure: Dust of dander, hair particles, and dried urine of rats
Preventive maintenance: Good exhaust ventilation.
3. Disease: Bagassosis
Exposure: Mouldy sugar cane
Preventive maintenance: Application of propionic acid to bagasse. Good exhaust ventilation. Keeping moisture content above 20%. The enclosure of processes.
4. Disease: Bird fanciers’ lung
Exposure: Droppings and feathers
Preventive maintenance: Good exhaust ventilation. Water spraying of droppings while cleaning.
5. Disease: Cheese washers’ lung
Exposure: Cheese mold
Preventive maintenance: Wrapping the cheese in foil during aging
6. Disease: Farmers’ lung
Exposure: Mouldy hay, straw, grain
Preventive maintenance: Dust Control
7. Disease: Hot tub lung
Exposure: Bacteria in mist from a hot tub
Preventive maintenance: Maintain disinfectant level for water. Regular hot tub cleaning. Good exhaust ventilation.
8. Disease: Maltworkers’ lung
Exposure: Mouldy malt
Preventive maintenance: Application of mechanical methods in the malting process.
9. Disease: Maple bark strippers’ disease
Exposure: Mouldy maple bark
Preventive maintenance: Spraying of logs during debarking. Remote control of some operations.
10. Disease: Mushroom workers’ lung
Exposure: Mouldy mushroom compost
Preventive maintenance: Good exhaust ventilation.
11. Disease: Sequoiosis
Exposure: Mouldy sawdust
Preventive maintenance: Good exhaust ventilation. The enclosure of processes.
12. Disease: Sewage sludge disease
Exposure: Dust of heat-treated sludge
Preventive maintenance: Good exhaust ventilation. At outside facilities, stand upwind of storage piles.
13. Disease: Wheat weevil lung / Miller’s lung
Exposure: Mouldy grain, flour, dust
Preventive maintenance: Dust Control
14. Disease: Suberosis
Exposure: Mouldy cork dust
Preventive maintenance: Good exhaust ventilation.
15. Disease: Wood pulp workers’ disease
Exposure: Mouldy wood chips
Preventive maintenance: Good exhaust ventilation. Remote control of some operations.
How can we reduce or prevent allergic alveolitis?
The means for dust control (reducing dust exposure) include personal protective equipment and engineering control. Education is equally vital, and these educational programs have to lay some emphasis on the significance of vegetable and animal dust in causing respiratory diseases.
It is also important that managers and workers also learn about methods of storing raw materials so as to prevent mold formation and also reduce dust.
The methods of engineering control include general ventilation, local exhaust ventilation, as well as separating the worker from the dusty process (process enclosure and process isolation).
On farms and gardens, it is possible to achieve the prevention of particle release as well as control of dust cloud formation through a well-designed, leakproof ducting, and enclosed conveyor systems specially designed for feeds and grains.
All buildings should have local ventilation systems in places that are frequented by workers who engage in egg-handling and feed preparation and storage.
Within all enclosed livestock units, it is vital that the temperature and relative humidity are regularly monitored. There should also be adequate ventilation and sufficient fresh replacement air.
For field operations, combine harvesters or tractors with enclosed cabs provided with filtered air should be provided for use.
While personal protective equipment is also vital, it should, however, be considered as a last resort for worker’s respiratory protection. Also, note that personal protective equipment is not to become a substitute for proper dust control.
For Respirators, which includes dust masks, they should only be used:
- when there is no technical feasibility for engineering or administrative controls.
- when emergencies or other temporary situations arise (e.g., maintenance operations).
- when engineering controls are being installed or repaired
If there is a need for respiratory protective equipment on the job, then it is vital that a complete respiratory program must be put in place. This will include selection, use, and also care for the respirators as well as education and training for the worker.
Note that respirators provide different levels of protection, thus it is very essential that the airborne contaminant is assessed before selecting any specific type of respirator. Did you find this article helpful? please leave a comment below if you have questions, suggestions, or contributions.
