Pulmonary Sarcoidosis

Sarcoidosis is a condition that occurs when groups of cells in your immune system form red and swollen (inflamed) lumps, known as granulomas, in any organ of the body. The inflammation that leads to these granulomas can be caused by infections or by certain substances in the environment.

Pulmonary sarcoidosis affects the lungs, causing inflammation and the formation of granulomas. While many cases resolve on their own or with treatment, some individuals may experience chronic disease or complications, including lung scarring.

Pulmonary sarcoidosis primarily affects the lungs and can present in various forms. The most common types include alveolar sarcoidosis, bullous sarcoidosis and necrotizing sarcoid granulomatosis. Less common types are miliary sarcoidosis and cavitatory pulmonary sarcoidosis.

The various types of pulmonary sarcoidosis include:

• Alveolar sarcoidosis: involves the air sacs (alveoli) of the lungs
• Bullous sarcoidosis: characterized by the formation of bullae, or air-filled pockets, in the lung tissue
• Necrotizing sarcoid granulomatosis: involves granulomas (inflamed areas) that can cause damage and tissue death to the lung vessels
• Miliary sarcoidosis: features small, disseminated granulomas throughout the lung tissue, often appearing as numerous tiny nodules
• Cavitary pulmonary sarcoidosis: involves the formation of cavities (holes) in the lung tissue, sometimes due to necrosis or the resolution of granulomas
• Pulmonary fibrosis (interstitial lung disease—ILD): scarring and thickening of the lung tissue, leading to reduced lung function and shortness of breath
• Pulmonary hypertension: increased blood pressure in the pulmonary arteries that can potentially lead to heart failure and shortness of breath

The cause of pulmonary sarcoidosis remains unknown. However, research suggests it results from a combination of genetic and environmental factors. Some individuals may have a genetic predisposition that makes them more susceptible, while environmental triggers, such as infections, dust or chemicals, can activate the disease. The immune system overreacts to these triggers, leading to inflammation and the formation of granulomas in the lungs.

Several factors are associated with an increased risk of developing pulmonary sarcoidosis, including genetic predisposition, environmental exposure and certain lifestyle choices. While these risk factors are not direct causes, they do enhance the likelihood of developing the disease. 

The risk of pulmonary sarcoidosis increases with the following conditions:

• Age: Individuals between the ages of 25 and 40 are most commonly affected.
• Ethnicity: People of both African and Scandinavian descent are most affected.
• Gender: Women are more often diagnosed with pulmonary sarcoidosis.
• Family history: Risk increases when a close family member has a diagnosis.
• Environmental factors
• Occupational exposures: Individuals working in fields such as agriculture, construction or metalworking are at risk of exposure to harmful substances, including mold, dust and silica.
• Weight-related compromised health
• Smoking: Smokers are at higher risk of pulmonary disease.

Some risk factors, such as your workplace, can be changed. But your age, family history and many other risk factors cannot be changed. Maintaining a healthy weight and lifestyle increases overall health and the body’s ability to recover from symptoms.

There are no screening tests to determine who will develop pulmonary sarcoidosis. If you are at risk, your healthcare provider may discuss with you ways to avoid certain substances in your environment that can trigger granulomas.

Many people with pulmonary sarcoidosis experience wheezing, coughing, shortness of breath, fatigue and chest pain. However, it is possible to have pulmonary sarcoidosis without these symptoms, and your condition can also affect other organs, leading to symptoms that may seem unrelated. Pulmonary sarcoidosis is diagnosed through a physical exam and imaging tests. Before making a diagnosis, your healthcare provider will rule out other potential conditions.

Your healthcare provider may have you undergo specific tests and procedures to diagnose pulmonary sarcoidosis, including:

• Chest X-rays are used to look for granulomas or scarring in the lungs and heart. This will also help figure out the stage of the disease. Often, sarcoidosis is found because a chest X-ray is done for another reason.
• A biopsy of the lungs may help confirm your diagnosis. Your doctor will do a bronchoscopy to get a biopsy sample from your lungs or lymph nodes in your chest.
• Other imaging tests can help identify granulomas or inflammation, including magnetic resonance imaging (MRI) scans or an ultrasound.
• Lung function tests are used to check whether you have breathing problems.

The goal of treating pulmonary sarcoidosis is remission, which means the condition persists but does not cause symptoms. Not everyone diagnosed with sarcoidosis requires treatment, as sometimes the condition resolves on its own. Your treatment will depend on your symptoms and how well your lungs are functioning. You may be given a treatment plan that includes one or more of the following:

• Medicines to lower inflammation or treat an overactive immune response. Immune-lowering medicines can raise the risk of infections.
• Inhaled corticosteroids or oxygen therapy to help with breathing problems
• Vasodilator treatment to relax your blood vessels
• Pulmonary rehabilitation to help you breathe more easily and be more active

If your pulmonary sarcoidosis goes into remission, your doctor may carefully discontinue your medications. However, you will still need to monitor for a flare-up. If a flare-up occurs, you may require another course of treatment. Flare-ups can be difficult to predict. Most often, they happen within six months of stopping treatment. The longer you remain symptom-free, the less likely you are to experience a flare-up.

Even if you do not have symptoms, it is recommended that you continue to see your healthcare provider for ongoing care so your care team can monitor for any side effects from long-term use of medications. If the disease is stable, you may be monitored closely to see whether it resolves on its own. If the condition does begin to worsen, your doctor can prescribe additional treatment.