You Wanted to Know: Sarcoidosis

Chest x-ray

Recently, I’ve received several questions about sarcoidosis, a relatively uncommon but serious health condition that can affect any organ in the body. One of my viewers, Julie, asked for more information about this disease on Twitter


Sarcoidosis is essentially an inflammatory disease. In sarcoidosis, the body’s immune cells begin to form clusters of cells called granulomas, which can accumulate in any organ – often in the lungs. As these granulomas grow, the organ’s function may start becoming impaired and symptoms can develop.

Symptoms of sarcoidosis depend largely on which part of the body is affected (and multiple areas often are). Though some people are asymptomatic and are only diagnosed after a chest x-ray shows an abnormality, others experience fatigue, fevers, swollen lymph nodes and/or unintentional weight loss. In addition, more than 90% of people with sarcoidosis have involvement of the lungs or thoracic lymph nodes, or signs on the skin or in the eyes. In a majority of cases, the lungs are involved, so many people experience a dry cough that won’t go away, shortness of breath, wheezing or chest pain. Up to a quarter of people with sarcoidosis develop skin signs, including tender red or purple bumps on the shin or ankles, sores on the nose, cheeks or ears, nodules just under the surface of the skin, or changes in the skin’s color. If the eyes are affected, people may experience blurred vision, eye pain, redness or light sensitivity.

In response to your specific question, Julie, sarcoidosis can affect the brain (a condition known as neurosarcoidosis), though this is very uncommon. In this case, weakness of the facial muscles is the most common symptom, and sensory loss may occur as well. The parts of the brain that affect temperature regulation, sleep or stress responses can also be affected. A lumbar puncture may show signs of inflammation in the nervous system, or an MRI may show abnormalities. Anyone with known sarcoidosis who develops neurological symptoms should seek emergency medical attention.

One of the reasons this disease is so hard to diagnose is that symptoms may be mild or severe, may begin gradually or suddenly, and may resolve themselves quickly or gradually worsen over years. Plus, doctors don’t currently know what causes sarcoidosis despite many, many studies investigating that very question. Environmental, genetic or infectious factors are all being investigated as possible causes, but nothing definitive has yet been concluded.

The outlook for sarcoidosis varies widely. Over half of people enter remission within three years of their diagnosis and two-thirds enter remission within 10 years, which means that while the disease isn’t active, it could return. Fortunately, after someone has been in remission for a year or more, less than 5% of people will relapse. One third of people with sarcoidosis have residual organ damage due to the disease. Neurosarcoidosis may be more severe that other types and may sometimes result in permanent damage or even death, particularly if it involves the brainstem.

Many people with sarcoidosis recover without any treatment, but all should be followed closely by a doctor. Anyone with involvement of the eyes, heart or brain requires treatment even if they don’t have symptoms. Anti-inflammatory drugs, anti-malarial drugs or immunosuppressants are often used to treat sarcoidosis. Ask your doctor if you’re concerned that you may have sarcoidosis.