Your immune system’s job is to keep you well, so when it encounters something that shouldn’t be in the body—bacteria, a virus or a foreign body—it mobilizes a response to eliminate the threat. Sometimes, when your immune cells can’t handle a threat quickly, they form into clumps called granulomas.
“Granulomas surround some foreign organisms to wall them off and prevent them from spreading,” says UNC Health pulmonologist Stephen Tilley, MD. “Granulomas typically form to fight off tuberculosis or fungal infections.”
In a condition called sarcoidosis, granulomas develop but aren’t the result of infection, and it’s not always clear why they formed in the first place. But depending on where they form and how large they get, these granulomas can cause a wide variety of symptoms.
“Sarcoidosis is considered a ‘snowflake disease’ because people are affected in such different ways,” Dr. Tilley says. “As a result, it can be unrecognized and underdiagnosed.”
Sarcoidosis is rare, with an estimated 150,000 to 200,000 cases in the United States, but Dr. Tilley says it’s helpful to know the symptoms and risk factors so that the condition can be considered when more common diagnoses have been ruled out. Here’s what you need to know.
Sarcoidosis Symptoms and Diagnosis
Sarcoidosis doesn’t always cause symptoms. Sometimes it can be diagnosed when a doctor spots enlarged lymph nodes on a chest X-ray or finds granuloma cells rather than tumor cells when doing a biopsy. Granulomas are almost always noncancerous.
Early symptoms may be similar to those of an infection and include fatigue, fever, body aches and swollen lymph nodes. From there, symptoms may depend on where the granulomas formed.
“Sarcoidosis can affect any organ in the body, but 90 percent of patients have symptoms related to the lungs or lymph nodes in the chest, which is why pulmonologists tend to see these patients,” Dr. Tilley says. “It can also affect the eyes and skin. More rarely, it can affect the heart, brain and the joints.”
Common lung symptoms include cough and shortness of breath. Heart symptoms include an irregular or fluttering heartbeat and dizziness or fainting. On the skin, there may be a rash or red bumps. Symptoms of sarcoidosis in the eyes include blurred vision, redness or swelling of the eyes, pain in the eyes or light sensitivity. There may be swelling or pain in the joints.
Symptoms may be limited to one system of the body, or you may have symptoms in multiple areas. They can vary in severity.
“These are nonspecific symptoms, so people might be misdiagnosed with a more common disease, like asthma,” Dr. Tilley says. “Sometimes you might be told you might have cancer, but the biopsy will show that it’s a granuloma instead of a tumor.”
Because these symptoms can be so common, diagnosing sarcoidosis usually means eliminating other possible disorders. While doctors can sometimes make the diagnosis by chest X-ray or CT scan, a biopsy is usually required to confirm the diagnosis.
Sarcoidosis Treatment
Most of the time, sarcoidosis resolves on its own, so you might not even know you had it. And even if you receive a diagnosis, you may not need treatment.
“About two-thirds of patients do not need any treatment,” Dr. Tilley says. “If a person has a cough and occasional shortness of breath but can tolerate the symptoms and isn’t showing declining lung function, we might follow closely for eight to 12 weeks before testing the lung function again.”
A third of patients will continue to experience symptoms, and for a small minority, these can progress and eventually cause permanent damage to affected organs.
If you have symptoms, your doctor likely will start by prescribing prednisone, a corticosteroid to reduce the inflammation caused by granulomas. Once resolved, sarcoidosis typically doesn’t recur.
For some people, sarcoidosis is chronic. Because prednisone comes with the risk of osteoporosis and cataracts if used for long periods, your doctor may try other medications that lower your immune system’s response or reduce inflammation.
Possible Causes of Sarcoidosis
It’s not clear why some people develop sarcoidosis, but it’s likely a combination of genetic and environmental factors such as working with certain dusts or materials used in building construction.
“Many patients have a history of exposure to particles in the air,” Dr. Tilley says. “They might work in demolition or construction or in a factory where they inhale particulates.”
Exposure to chemicals or dust wouldn’t necessarily cause sarcoidosis on its own; people who develop it likely have a gene mutation that causes the immune system to respond this way to the presence of particles, Dr. Tilley says.
A diagnosis of sarcoidosis is often delayed because it is rare and its symptoms mimic other, more common diseases. Dr. Tilley suggests talking to your doctor if you have family members with sarcoidosis, or if you have been diagnosed with another lung disease but are not improving with treatment.
“If you have persistent symptoms, it may be worth asking your doctor if you could have sarcoidosis,” Dr. Tilley says.
Concerned about symptoms? Talk to your doctor. If you need a doctor, find one near you.