What Is Sarcoidosis?

Sarcoidosis is a systemic inflammatory disease that develops when groups of cells in the immune system form clumps called granulomas in various parts of the body. The condition can affect all organs in the body, but cases are typically found in the lymph nodes and lungs. Some cases of sarcoidosis are mild and do not require treatment, but some can be life-threatening and result in permanent organ damage. It is typically diagnosed in adults between 20 and 40 years old.

Sarcoidosis is a rare disease. Research estimates that there are fewer than 200,000 cases each year in the United States. The incidence of the disease is much higher among African Americans compared with Caucasians, and African Americans are more likely to have a more severe form of sarcoidosis.

Types of Sarcoidosis

There are nine types of sarcoidosis, each of which is characterized by inflammation and abnormal cell deposits in different parts of the body:

• Cardiac sarcoidosis: The formation of granulomas in the heart leads to cardiac sarcoidosis. This form of sarcoidosis is diagnosed in 2% to 5% of people with systemic sarcoidosis, but some reports have shown that as many as 20% to 30% of sarcoidosis patients in the United States may have cardiac sarcoidosis. Cardiac sarcoidosis is the second leading cause of death from sarcoidosis, which is usually caused by heart block or ventricular arrhythmia.
• Ocular/eye sarcoidosis: Sarcoidosis can affect the eyes and lead to uveitis, which is inflammation of the eye that can cause vision loss and eye pain. Ocular involvement in sarcoidosis is present in up to 80% of patients and is usually manifested before the disease is diagnosed.
• Pulmonary/lung sarcoidosis: Pulmonary sarcoidosis is the most prevalent of all types of the disease, and can lead to weakened lung function. Pulmonary sarcoidosis occurs in up to 90% of all cases of the condition, and 10% to 20% of people with sarcoidosis will develop treatment-resistant pulmonary disease like pulmonary fibrosis and pulmonary hypertension, which are the leading cause of death from sarcoidosis.
• Neurosarcoidosis: This type of sarcoidosis is chronic and affects the central nervous system, including the brain, spinal cord, and optic nerve. Neurosarcoidosis is involved in roughly 5% to 10% of all cases. Weakness of the facial muscles on one side of the face (Bell’s palsy) is a common symptom of neurosarcoidosis. This condition can also lead to vision and hearing loss.
• Musculoskeletal sarcoidosis: It is rare for sarcoidosis to affect the musculoskeletal system: It occurs in roughly 10% to 15% of cases, and can lead to issues with muscles, joints, and bones, leading to inflammatory arthritis, soft tissue swelling, and bone loss.
• Cutaneous sarcoidosis: The symptoms of this type of sarcoidosis, like papules and plaques, mimics other dermatological conditions, making it difficult to diagnose. Sarcoidosis of the skin occurs in 25% of all sarcoidosis cases.
• Renal sarcoidosis: When granulomas form in the kidneys, it can lead to renal dysfunction and even kidney failure in severe cases. This type of sarcoidosis may also cause the formation of kidney stones made up of calcium. Renal sarcoidosis accounts for up to 25% to 30% of all sarcoidosis cases.
• Hepatic sarcoidosis: Hepatic sarcoidosis occurs in the liver. It appears in up to 70% of all sarcoidosis cases. The liver can become enlarged, and people with this type of sarcoidosis will have abnormal liver tests or cirrhosis.
• Sarcoidosis of the spleen and bone marrow: When sarcoidosis affects the spleen and bone marrow, it can lead to health issues like anemia and leukopenia. Roughly 26% of all sarcoidosis cases will affect the spleen or bone marrow.

Sarcoidosis Symptoms

The symptoms of sarcoidosis will differ depending on where in the body granulomas have formed, but all forms of the disease can present with similar symptoms. Sometimes people with the condition will be asymptomatic, making sarcoidosis hard to diagnose.

General Symptoms

The general symptoms of sarcoidosis are nonspecific and could sometimes be confused for those of other conditions. The most common initial symptoms of sarcoidosis include:

• Fatigue
• Swollen lymph nodes
• Weight loss
• Joint pain and swelling

Cardiac Symptoms

The main symptoms of cardiac sarcoidosis include:

• Heart block
• Chest pain
• Enlargement of the right side of the heart
• Cardiomyopathy
• Dysrhythmias
• Palpitations
• Dizzy spells
• Arrhythmias
• Sudden death

Eye Symptoms

The biggest indicator of ocular sarcoidosis is inflammation of the eye. Ocular form of the disease can present with the following symptoms:

• Blurred vision
• Teary eyes
• Light sensitivity
• Glaucoma
• Cataracts
• Blindness
• Dry eyes

Lung Symptoms

The symptoms of pulmonary sarcoidosis will not appear in everyone with the condition and will range in severity depending on the severity of the disease. The most common symptoms include:

• Shortness of breath that worsens with activity
• Persistent dry cough
• Chest pain
• Wheezing

Other symptoms that aren’t related to the lungs but can appear in pulmonary sarcoidosis include:

• Fatigue
• Fever
• Night sweats
• Joint and bone pain
• Skin rash, new lumps, or pigmentation changes in the face, arms, or shins
• Weight loss
• Swollen lymph nodes
• Eye inflammation that presents with pain, burning, blurred vision, and light sensitivity

Skin Symptoms

The skin symptoms sarcoidosis include:

• Tender or painful skin
• Reddish patches or bumps
• Swelling and pain in the joints
• Purple lesions on the cheeks, lips, nose, and ears known as Lupus pernio
• Plaques or patches without color
• Skin nodules
• Hair loss

Causes

Although there is no known cause for any type of sarcoidosis, it is thought that both genetics and environmental factors play a role in its development. It is suggested that when someone whose genes make them more prone to developing sarcoidosis is exposed to a trigger such as an infection or environmental contaminant, their immune system can overreact and start the development of the disease.

Some studies have found antibodies against human proteins at increased rates in some patients with sarcoidosis compared to others with and without sarcoidosis. The cells from some people with sarcoidosis also demonstrate an immune response to some of their own proteins, similar to autoimmune diseases. The exact role of autoimmunity in sarcoidosis is not clear yet, and sarcoidosis is currently not considered an autoimmune disease.

Another theory suggests that sarcoidosis may be caused by a bacterial infection. The research behind this theory found that the majority of samples taken from people with the disease were found to contain the Propionibacterium acnes bacteria. Viruses and chemicals may also trigger the disease.

Risk Factors

Certain factors may lead to a higher risk of developing the disease, including:

• Working in moldy or dusty environments
• African American descent
• Female sex
• Family history of sarcoidosis
• Age (between 20 and 40 years old)

Diagnosis

Diagnosing sarcoidosis is often challenging because there is no single blood or imaging test that can clinch the diagnosis.

Instead, the diagnosis of sarcoidosis is based on four main factors:

• A detailed medical history and complete physical exam
• Imaging and other diagnostic tests
• A sample (biopsy) of affected tissue
• Diagnostic studies that rule out potential diseases that mimic sarcoidosis

Given that sarcoidosis may not present with symptoms, the disease is sometimes discovered incidentally when a person has a physical exam or a chest X-ray for some other reason.

Medical History and Physical Exam

During the medical history, a healthcare provider may become suspicious for sarcoidosis if a patient's main symptoms are lung-related and accompanied by constitutional symptoms, like fever.

In addition, a patient's age and race can provide a clue to the potential diagnosis. More than 80% of sarcoidosis cases occur in adults between the ages of 20 and 50. Moreover, African-Americans are approximately three to four times more likely to develop sarcoidosis than whites.

When it comes to the physical exam, signs of sarcoidosis are often subtle or nonspecific, such as wheezing heard in the lungs.

That said, in some cases, the physical exam findings are more obvious, and if they are found in combination (for example, the eruption of an erythema nodosum rash, along with a fever and multiple joint pains), the diagnosis of sarcoidosis becomes more evident.

Imaging and Other Diagnostic Tests

A variety of imaging and other tests are usually performed to help make the diagnosis of sarcoidosis.

These tests often include the following:

• Chest X-ray: The two classic findings seen on a chest X-ray of a patient with sarcoidosis are enlargement of the lymph nodes on both sides of the chest (bilateral hilar lymphadenopathy) and pulmonary (lung) infiltrates
• High resolution computed tomography (HRCT) scan of the chest
• Pulmonary function tests (PFTs)
• Electrocardiogram (ECG)
• Various blood tests: Angiotensin-converting enzyme (ACE) level, complete blood count (CBC), and comprehensive metabolic panel (CMP), to name a few
• Urinalysis and urine calcium level
• Eye exam

Biopsy

During a biopsy, a small sample of tissue is removed from an organ that is affected by sarcoidosis. A biopsy may be performed on the lung or other affected organ or tissue, like a lymph node, area of skin, or enlarged parotid gland. Sometimes, two different organs are biopsied to help make the diagnosis of sarcoidosis.

Once the tissue sample is removed, it is examined under a microscope for the characteristic finding of sarcoidosis—a granuloma.

Differential Diagnoses

Several other diseases can mimic the symptoms and signs of sarcoidosis, which is why your healthcare provider will evaluate these alternative diagnoses:

• Infections, like tuberculosis, histoplasmosis, or human immunodeficiency virus
• Cancer, like lymphoma
• Drug-induced hypersensitivity
• Foreign body granulomatosis
• Hypersensitivity pneumonitis
• Pneumoconiosis (e.g., aluminum or beryllium)
• Vasculitis, like Churg-Strauss syndrome or granulomatosis with polyangiitis (formally called Wegener granulomatosis)

Treatment

There is no cure for sarcoidosis, but the condition sometimes resolves without medical intervention. For those who do require treatment, the severity of symptoms will be the deciding factor in the type of treatment used.  

Medications

If a case of sarcoidosis is particularly severe, medication will likely be prescribed to help combat symptoms and slow the progression of the disease. Some medications used in the treatment of sarcoidosis include:

• Corticosteroids or prednisone: Helps slow down the immune system thus reducing inflammation 
• Methotrexate: Suppresses the immune system
• Antimalarials: Help with skin and joint symptoms
• TNF inhibitors: Help with inflammation
• Corticotropin: Helps the body produce natural steroid hormones
• NSAIDs: Help reduce inflammation and relieve arthritic symptoms

Other Treatments

Depending on what part of the body was affected, the treatments may vary. Some possible treatments for more progressed stages of sarcoidosis include:

• Physical rehabilitation to help restore lung function and alleviate fatigue
• Physical therapy to help improve muscle and slow joint damage
• Organ transplantation if the organ affected is severely damaged
• Eye care if the eyes are affected

Although organ transplantation is a treatment option, it is rarely used for those who have kidney or lung failure.

Prognosis

The prognosis for people with sarcoidosis differs depending on symptoms, the level of damage done to the body, and the type of sarcoidosis they have. For many, recovery typically occurs on its own without medical intervention. In about 60% of cases, the granulomas will disappear over a period of two to five years and the patient will recover. 

In rare cases, the condition can lead to death if the body is damaged irreparably, like severe scarring of the lungs, although that only occurs in roughly 1% to 8% of sarcoidosis cases. If no treatment is required, you should see your healthcare provider for regular check-ups to ensure that it is monitored accordingly and isn’t progressing.

Signs that warrant additional caution and monitoring include:

• Gradual onset of the inflammation that elicits symptoms and organ harm
• Granulomas affecting multiple organs
• Older patients
• Patients of African American descent

Coping

Sarcoidosis comes with health challenges that can be difficult to cope with. If that is the case with you, a support group can be a big help in coping with the condition and the effects that it has on your life. The Foundation for Sarcoidosis Research has an online database that can help connect people with sarcoidosis with a support group in their local area.

The Lung Helpline (1-800-LUNGUSA) by the American Lung Association is staffed by experienced registered nurses, respiratory therapists and certified tobacco treatment specialists and can answer any questions related to the condition. 

Managing a chronic condition like sarcoidosis can be physically and mentally taxing, so self-care is an important component of coping with the disease. People with sarcoidosis can take care of themselves by discussing their symptoms with their loved ones. They can also find creative outlets for their stress like painting and journaling.

A Word From Verywell

If you have sarcoidosis and are undergoing treatment or monitoring, it’s important to remember to keep up with your medications and appointments. The severity of the disease and its progression can be slowed with proper treatment.

Living life with a chronic disease is never easy, but it can be made easier by following certain medical requirements so you can live a full and happy life with sarcoidosis. Reaching out to others who share the same experiences can also help you cope with this chronic condition.