Sarcoidosis

This article was last reviewed on

7 June 2018.

This article waslast modified on 2 February 2019.

What is sarcoidosis?

Sarcoidosis is a condition in which inflammatory cells produce nodules called granulomas in multiple organs. Granulomas can develop anywhere in the body, but they commonly affect the lungs, skin, lymph nodes, and eyes. Granulomas change the structure of the tissues around them and, in sufficient numbers they can cause damage, inflammation and symptoms and may interfere with normal functions.

The cause of sarcoidosis is not known. The condition is thought to be associated with both a genetic predisposition and the immune system's reaction to an environmental trigger – such as exposure to a virus, bacteria, allergen, dust, or chemical. . The incidence of sarcoidosis appears to be higher in Scandinavian countries and in Afro-Caribbean people, and also marginally higher in women. In general, incidence peaks between the ages of 20 and 50 years, with a second smaller peak after the age of 60. . In the UK, the incidence of the condition is estimated to be about 3/100,000 person-years based on general practice data. Sarcoidosis varies in severity. A person may have the disease without knowing it as mild cases cause no, few, or nonspecific symptoms. It can cause acute illness, resolve on its own within a few years (remission), recur, or continue as a chronic condition involving several organs causing severe symptoms and functional impairment. More than half of those affected will go into remission within 3 years of diagnosis, and two-thirds will be in remission within 10 years.

Most people with sarcoidosis will not experience long-term health effects, but about one-third will have some degree of organ damage. Sarcoidosis can cause blindness in rare cases and can sometimes be fatal, primarily in those with severe lung or heart involvement. The lungs are involved in most cases and are affected without other organ disease in approximately 50% of patients; the skin, liver and eyes are the most frequent extrapulmonary sites. There are significant differences in severity of disease and organ involvement depending on the ethnicity of the patient.

About Sarcoidosis

Signs and Symptoms
The severity of sarcoidosis and the symptoms a person experiences depend upon the tissues and organs affected. A person may have no symptoms or may have nonspecific findings such as:

Fever

Fatigue

Weight loss

Night sweats

Loss of appetite

Swollen lymph nodes

Joint pain

Signs and symptoms associated with specific organs are listed below.

Classification:

Commonly used classification according to organ/system involvement

Systemic sarcoidosis

It involves more than one organ or system. Symptoms may be non-specific or related to organ involved and sometimes with chronic fatigue.

Lungs

The American Lung Association estimates that as many as 90% of those with sarcoidosis will have lung involvement. Lung tissues may stiffen and scar tissue may develop. Those affected may have:

Dry cough

Wheezing

Shortness of breath

Chest pain

Skin

Skin is the second most commonly affected organ. Up to 25% of those with sarcoidosis have skin problems, including:

Sores on or near the cheeks, ears, nose, and eyelids

A raised, reddish, bumpy rash on the ankles or shins that may itch or be tender and warm

Discoloured skin

Inflammation and nodules around scars

Eyes

Blurred vision

Sensitivity to light

Eye pain and itching

Burning and redness

Tears

Inflammation

Heart

The heart is affected in about 5% of those with sarcoidosis.

Abnormal heart rhythm

Congestive heart failure

Cardiomyopathy

Brain and Nervous System

Headaches

Weakness

Seizures

Decreased coordination and tremors

Muscle and Bone

Pain

Joint stiffness

Sarcoidosis can also cause kidney and liver dysfunction, an enlarged liver or spleen, and swollen salivary glands. It can alter the way the body processes calcium, leading to increased calcium in the blood and urine and the formation of kidney stones. In rare cases, it may cause kidney failure.
Tests
The goals with testing are to diagnose sarcoidosis, evaluate its severity, and to monitor its course over time. Testing is also used to distinguish sarcoidosis from conditions with similar symptoms and from conditions that are also associated with the development of granulomas – such as tuberculosis and some fungal infections.

Laboratory Tests

Tissue biopsy is the primary test used to confirm a diagnosis of sarcoidosis; characteristic changes in the structure of the tissue can be seen under the microscope. The sites of biopsy are lung and skin. Other laboratory tests are not specific for sarcoidosis, but they are helpful in assessing disease activity, looking for damage to individual organs, and ruling out other diseases that may cause similar problems. Tests that may be requested include:

ACE (Angiotensin converting enzyme) - often elevated in patients with sarcoidosis but may be increased with other conditions; this test is used to help diagnose sarcoidosis, but is not reliable enough on its own to diagnose the condition. It is useful in monitoring disease activity, and response to treatment.

Calcium to detect increases in the blood or urine. Hypercalciuria (increased calcium in urine) occurs in about 50%, while hypercalcaemia (increase blood calcium) can be found in about 5% of patients with Sarcoidosis. A spot urine calcium or 24-hour collection of urine may be ordered to rule out hypercalciuria. Fasting is not required before taking blood for calcium measurement.

ESR (Erythrocyte Sedimentation Rate) - sometimes requested to detect inflammation

Liver Function Tests and/or Renal Profile - a group of tests used to evaluate liver and/or kidney function, to determine if those organs are affected

FBC (Full Blood Count) - may be requested to evaluate red and white blood cell changes

CSF analysis - an evaluation of the cerebrospinal fluid when brain or nervous system involvement is suspected

AFB cultures, sputum cultures, and fungal tests - to help distinguish between sarcoidosis and other conditions associated with the lungs and with granuloma development

Non-Laboratory Tests

X-ray - one of the primary tests used to detect lung involvement; granulomas may be initially detected in people without symptoms who have an X-ray for another reason. The disease can be staged according to the appearance of the lungs on the chest X-ray which aids in treatment options.

Lung function tests are performed to evaluate lung involvement, lung capacity, and condition severity. (For more on these, visit the Royal Brompton and Harefield NHS Foundation Trust website.). The airways can be visualized by flexible bronchoscopy and may yield a brushing, lavage or a tissue biopsy.

CT (Computed Tomography), MRI (Magnetic Resonance Imaging), gallium scan, or other imaging scans are sometimes requested to help diagnose and evaluate sarcoidosis. ECG (electrocardiogram) - sometimes requested when heart involvement is suspected
Treatment
There is no way to prevent or cure sarcoidosis, but in many cases it will resolve on its own over time. The prognosis is generally good and sarcoidosis resolves in most people within 2 to 5 years; however, about 25% of people will develop residual fibrosis in the lungs or elsewhere. Disease related mortality is reported to be about 5%, with the most common causes of death being from lung, cardiac and neurological disease that is refractory to therapy. The goals of treatment are to relieve symptoms, decrease inflammation, and to minimise tissue and organ damage. People who have few or mild symptoms may not need treatment, but their condition should be monitored.

Those with moderate to severe symptoms and those at risk for tissue or organ damage are usually treated with corticosteroids such as prednisone. Oral corticosteroids are the first line of therapy in patients with progressive disease determined by radiology or on lung function, significant symptoms or extrapulmonary disease requiring treatment. Topical or inhaled corticosteroids may be considered in some sub group of patients depending on organ involvement and disease severity. . Long-term use of corticosteroids can cause significant side-effects. (eg; bone loss or osteoporosis)

Other medications may include:

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for pain and inflammation

Methotrexate and other drugs that suppress the immune system for lung, skin, or eye involvement

Hydroxychloroquine (an anti-malarial drug) may be useful for skin and nervous system involvement, especially in people who have increased calcium levels

Cyclosporin and cyclophosphamide are immunosuppressant medications considered in patients when corticosteroids are not controlling the disease or cause intolerable side effects.

Other treatment options include azathioprine, chlorambucil, leflunomide, pentoxifylline, and thalidomide.

“Biologics” are newer medications that can be used, and include infliximab, a biological human monoclonal antibody, and Etanercept. These medications can be used to reduce disease severity in lung invlovement.

Patients taking long-term corticosteroids are advised to take calcium and vitamin D supplements for osteoporosis prevention. Those with a diagnosis of osteoporosis may also need oral bisphosphonates or other anti-osteoporosis medications.

Most people can be successfully treated, but they may need to take medications for an extended period. Rarely, a person may need an organ transplant if the lungs or liver have become severely damaged.

Monitoring and follow up

Follow-up is generally at 3-6 months intervals, more frequent in first 2 years of diagnosis and in more advanced stages of the disease. Monitoring includes clinical signs of disease and blood tests (e.g., FBC, liver and renal profile, calcium). Bone density scans may perform regularly in patients who are taking medications that are associated with bone loss.