Pneumonitis – Symptoms and Causes
Overview
Pneumonitis is inflammation of lung tissue not caused by infection. It occurs when the immune system reacts strongly to an irritating substance.
People can develop pneumonitis from exposure to airborne irritants at work, home, or during hobbies. Some medications and cancer treatments can also trigger this condition.
The main symptoms include breathing difficulties and a dry cough. Unlike pneumonia, which is caused by infection, pneumonitis results from the body’s defensive reaction to irritants.
Common causes include:
- Workplace airborne particles
- Home environmental irritants
- Hobby-related exposures
- Certain medications
- Some cancer treatments
Treatment primarily involves avoiding the triggering irritants and reducing the inflammation in the lungs. Proper diagnosis and management are important for preventing long-term lung damage.
Signs and Symptoms
Pneumonitis can develop either suddenly or gradually, with symptoms that may change over time.
People with this condition often experience different symptoms, which can include:
- Breathing difficulties
- Dry cough without mucus
- Severe fatigue
- Reduced hunger
- Elevated body temperature
- Pain in muscles and joints
- Headache
- Dropping weight
Sometimes these symptoms may quickly improve or worsen without warning.
When Medical Help Is Needed
Contact your healthcare provider if you notice ongoing breathing problems or a persistent dry cough. These symptoms shouldn’t be ignored.
If you experience severe breathing difficulties, don’t wait – seek emergency medical attention immediately. In the United States, call 911 or go directly to the nearest emergency room.
What Triggers Lung Inflammation
Allergic Lung Reactions
Hypersensitivity pneumonitis occurs when the immune system overreacts to certain particles in the air. This creates inflammation in the lungs’ tiny air sacs. The condition has several nicknames based on its cause, like “farmer’s lung” or “hot tub lung.”
Common triggers include:
- Mold Spores: Found in damp hay, poorly maintained hot tubs, home humidifiers, air conditioners, and water-damaged buildings.
- Bird Materials: Feathers, droppings, and dust from birds.
- Wood and Metal Dust: Released during woodworking or metalworking.
- Chemical Sprays: Including pesticides and industrial chemicals.
- Animal Products: Skin cells, fur, and waste from farm animals and pets.
People react differently to these substances. Someone might develop severe inflammation after minimal exposure, while others remain unaffected even with regular contact.
Medicine-Related Inflammation
Some medications can damage lung tissue and cause pneumonitis. The exact process isn’t fully understood, but researchers believe these drugs may either directly irritate lung cells or trigger an abnormal immune response.
Medications that commonly cause lung inflammation include:
| Drug Type | Examples |
|---|---|
| Antibiotics | Certain types used for serious infections |
| Cancer treatments | Many chemotherapy drugs |
| Heart medications | Some rhythm-controlling medicines |
Symptoms typically develop gradually and may improve when the medication is stopped.
Radiation Treatment Effects
Radiation therapy for chest cancers sometimes damages healthy lung tissue alongside cancer cells. This damage can trigger inflammation in the lungs.
Patients receiving radiation for:
- Breast cancer
- Lung cancer
- Lymphoma
- Whole-body radiation before bone marrow transplants
Are at higher risk for developing pneumonitis. Symptoms usually appear within 2-3 months of completing treatment. The risk increases with higher radiation doses and when larger areas of the lung are treated.
For many patients with pneumonitis, doctors never identify the exact cause despite thorough testing. This makes treatment challenging but not impossible.
Risk Factors
Environmental Factors
People who work in certain jobs face higher risks of pneumonitis. Farmers often breathe in mold particles during grain and hay harvests.
Those working with fine mists, fumes, dust, and chemicals also face increased danger. Woodworkers may have higher risks too.
Handling birds and animals creates exposure risks. People who work with poultry or breed pigeons often contact droppings, feathers, and other materials that might trigger pneumonitis. Regular exposure to many animals can increase your risk as well.
Home environments matter too. Poorly maintained hot tubs and humidifiers can develop mold growth. Any place where mold thrives becomes a potential risk factor for developing pneumonitis.
Cancer Treatments
Some cancer medications can lead to pneumonitis as a side effect. Radiation therapy directed at the lungs or chest area may also cause this condition. When patients receive both radiation and certain medications together, their risk increases significantly.
Genetic Factors
Your genes might make you more likely to have strong immune reactions to certain substances. If your family members show pronounced allergic responses, you may have inherited a genetic tendency for similar reactions.
This genetic predisposition can increase your risk of developing pneumonitis when exposed to triggering substances.
Possible Problems
When pneumonitis goes undetected or untreated, it can lead to permanent lung damage. This damage cannot be reversed once it develops.
Normal lungs have air sacs that expand and contract with each breath. When inflammation continues for a long time, the thin tissue lining these air sacs becomes scarred.
This scarring makes the air sacs stiff and inflexible, similar to a dried sponge.
This condition is called pulmonary fibrosis. Severe cases can cause serious health issues including high blood pressure in the lungs, right-sided heart failure, respiratory failure, and death in extreme cases.
