Sarcoidosis

What is Sarcoidosis?

Sarcoidosis is a disease that can affect multiple parts of the body and we don’t know precisely what causes it. It is commonly found in young adults around the world. This condition creates small, benign lumps called noncaseating granulomas in different organs. A common symptom of sarcoidosis is the swelling of the lymph nodes located on either side of the lungs along with net-like marks in the lungs. It often affects the skin, eyes, and joints too. However, it can also show up in varying degrees in the muscles and bones, part of the immune system known as the reticuloendothelial system, sweat glands, heart, kidney, and the brain and spinal cord, which together form the central nervous system.

What Causes Sarcoidosis?

Sarcoidosis is an inflammatory disease and doctors aren’t exactly sure what causes it. It shows up as non-caseating granulomas, which are clumps of cells that form in various parts of the body. Certain career-based and environmental factors, like being exposed to a metal called beryllium, dust or other substances that can cause asthma, have been linked to the disease. Some bacteria, like mycobacteria and propionibacteria, have also been associated with sarcoidosis.

It’s also been observed that sarcoidosis can develop in a person who was previously healthy after they’ve had a heart or bone marrow transplant. This discovery has led to some research into whether infections could be a cause of sarcoidosis in some cases.

There is a genetic aspect to the disease as well. People who have more than one family member with the disease usually share similar features in their major histocompatibility complex (MHC), which is a part of the immune system that helps the body recognize foreign substances. In these cases, similar patterns were found especially with something called DR alleles, which are specific types of MHC. Some studies have also found other less common genes and differences in the way the body processes a hormone called angiotensin, but these were only in a few patients.

Certain proteins that the body produces during an immune response, known as cytokines, have been closely linked to sarcoidosis. This includes Th1, IL-2, IL6, IL 8, IL12, IL 18, IL 27, interferon gamma and tumor necrosis factor alpha. Some of these proteins are involved in the formation of the granulomas, encouraging certain cells like macrophages and epithelioid cells to gather and become active. Other proteins are believed to affect the course of the disease.

Risk Factors and Frequency for Sarcoidosis

Sarcoid, a type of disease that can affect various parts of the body, is more common among African Americans, with 34 cases per 100,000 people, while whites have 11 cases per 100,000. In the United States, the chance of getting this disease in your lifetime is about 2.4%. It’s important to note that up to 25% to 30% of people with this disease can have it in parts of their body other than the lungs. Interestingly, males tend to see more heart-related issues, whereas skin and eye symptoms are usually more common in females. These non-lung related symptoms can vary in when they show up, who they affect, and their prevalence among different ethnic groups.

Signs and Symptoms of Sarcoidosis

Sarcoidosis is a condition that can cause a variety of symptoms. These typically include a consistent dry cough, fatigue, and difficulty breathing. Other symptoms can include:

Skin lumps that are red and painful
Blurry vision caused by uveitis
A hoarse voice
Swollen lymph nodes in areas like the armpit and neck
Joint swelling and pain
Hearing loss
Seizures
Mental health issues like depression and anxiety which are part of neurological symptoms
Heart problems like cardiomyopathy and conduction defects
Kidney stones (renal calculi)
An enlarged liver

There can also be different skin reactions (which are referred to as cutaneous manifestations), including raised bumps (papular sarcoidosis), which are often seen on the face, neck, and scar sites. Other skin conditions related to sarcoidosis include a variant called Lupus pernio, characterized by violet or red bumps mainly on the face. Non-tender subcutaneous nodules under the skin and plaque-like lesions are also common.

Erythema nodosum, characterized by painful nodules on the lower legs (shins), is also frequently seen in sarcoidosis. This condition can sometimes show up years after an injury or getting a tattoo.

Eye problems (ocular manifestations) are observed in about half of the patients, with the most common being uveitis. Significant heart issues, including heart block and sudden death, can occur in sarcoidosis, and in some instances, it’s suggested to have a cardioverter-defibrillator implanted for preventive measures.

Central nervous system (CNS) outcomes can involve diabetes insipidus and an increase in the hormone prolactin (hyperprolactinemia). Those with severe symptoms tend to have a lower quality of life and often experience mental health issues, including depression and anxiety.

Testing for Sarcoidosis

If your doctor suspects that you may have a condition known as sarcoidosis, several lab tests may be required. These tests will check for various things such as abnormal aspects of your blood, liver function, and levels of different substances in your blood. They’ll look for signs of anemia (a lack of sufficient red blood cells), leukopenia (low white blood cell count), and thrombocytopenia (low platelet count). Other tests will check aspects like your blood urea nitrogen, creatinine, glucose, electrolytes, and serum calcium which could indicate different medical conditions. You might also have to undergo some serologic tests, which are designed to identify and measure certain substances related to your immune system activity.

Aside from laboratory tests, imaging scans could also be part of the diagnosis process. Since sarcoidosis primarily affects the lungs, you may need a chest x-ray, a CT scan of the chest, or even more specialized scans. If the disease might have spread to your heart or brain, an MRI or PET scan could be beneficial. If you’ve been experiencing unexplained difficulty breathing or coughing and your chest X-ray did not show anything unusual, a high-resolution CT scan of your chest might be suggested.

Pulmonary function tests might be conducted. These measure how well your lungs work. In advanced cases, this test might reveal a decrease in DLCO (which measures how well oxygen travels from your lungs into your blood) and a restrictive pattern of breathing. Some patients may even have an obstructive breathing pattern. Additional testing may be needed for patients with severely reduced DLCO and oxygen saturation levels.

There are four stages that doctors use to categorize the severity of lung sarcoidosis, related to lymph node enlargement and the presence of reticular opacities (shadowy areas seen on X-ray images).

Sarcoidosis is known to cause a specific type of lung tissue inflammation known as noncaseating granulomas, characterized by clusters of immune cells such as epithelioid histiocytes, giant cells, and mature macrophages. To confirm this, a biopsy (taking a small tissue sample for examination) is typically required. This could be a transbronchial biopsy (taking a sample from inside your bronchial tubes) or, if that doesn’t work, a mediastinoscopy (a procedure to take a sample from your lymph nodes). The biopsy serves to ensure that these granulomas are not caused by similar-appearing but fundamentally different conditions such as tuberculosis or fungal infections.

Treatment Options for Sarcoidosis

Pulmonary sarcoidosis, a condition that affects the lungs, often shows no symptoms and does not get worse over time. Therefore, it doesn’t usually require treatment. In fact, a lot of people with the condition see it go away by itself. Doctors typically keep an eye on patients who don’t show symptoms by regularly checking their lung condition with imaging tests and lung function tests every three to six months.

However, in cases where pulmonary sarcoidosis causes symptoms to worsen or the disease progress to stages II or III (as seen in X-ray images), the use of medications called oral glucocorticoids may be considered. These medications can help control the inflammation in the lungs. If there’s no noticeable improvement in symptoms or the lung condition seen in X-ray images, or the lung function tests within 4 to 6 weeks, then doctors might choose to continue giving patients these medications for an additional four to six weeks. It’s also important to note that these medications are typically lowered slowly or “tapered” over six to eight months.

For patients who can’t take glucocorticoids, alternatives like methotrexate, azathioprine, infliximab, leflunomide, and antimalarial drugs can be considered. These are known as ‘steroid-sparing agents’ – basically, alternatives to steroids.

For patients who have severe lung damage due to the disease (also known as end-stage lung disease), lung transplant could be an option. However, this is a major surgery with its own risks and it also requires the patient taking life-long medications to suppress the immune system (immunosuppressive therapy), in order to prevent the body from rejecting the new lung.

Tuberculosis
Cat scratch disease
Lung cancer
Lymphoma
Occupational lung disease
Fungal infection

What to expect with Sarcoidosis

Patients who don’t have any symptoms often don’t need any treatment and can remain stable for many years. However, those who start showing signs of having lung issues or diseases that affect other parts of the body often have uncertain outcomes. It’s also common for their symptoms to return, and many such patients develop difficulty breathing and high blood pressure in the lungs when the disease progresses.

The overall death rate for patients who receive no treatment is about 5%. However, long-term treatment with corticosteroids, drugs often used to reduce body inflammation and aid in healing, may not be harmless. This is because common side effects can occur from using these drugs.

Possible Complications When Diagnosed with Sarcoidosis

High blood pressure in the lungs
Severe, irreversible lung disease

Frequently asked questions

The prognosis for sarcoidosis varies depending on the individual and the severity of the disease. Some patients with no symptoms can remain stable for many years without needing treatment. However, for those who develop lung issues or diseases affecting other parts of the body, the outcomes can be uncertain. It is common for symptoms to return and for patients to experience difficulty breathing and high blood pressure in the lungs as the disease progresses. The overall death rate for patients who receive no treatment is about 5%.

Doctors aren't exactly sure what causes sarcoidosis, but certain career-based and environmental factors, like exposure to beryllium, dust, or other substances that can cause asthma, have been linked to the disease. Some bacteria, like mycobacteria and propionibacteria, have also been associated with sarcoidosis. Additionally, sarcoidosis can develop in a person who was previously healthy after they've had a heart or bone marrow transplant. There is also a genetic aspect to the disease, as people who have more than one family member with sarcoidosis usually share similar features in their major histocompatibility complex (MHC), which is a part of the immune system that helps the body recognize foreign substances.

Signs and symptoms of Sarcoidosis include: - Consistent dry cough - Fatigue - Difficulty breathing - Skin lumps that are red and painful - Blurry vision caused by uveitis - A hoarse voice - Swollen lymph nodes in areas like the armpit and neck - Joint swelling and pain - Hearing loss - Seizures - Mental health issues like depression and anxiety which are part of neurological symptoms - Heart problems like cardiomyopathy and conduction defects - Kidney stones (renal calculi) - An enlarged liver In addition, there can be different skin reactions, including raised bumps (papular sarcoidosis) on the face, neck, and scar sites. Another skin condition related to sarcoidosis is Lupus pernio, characterized by violet or red bumps mainly on the face. Non-tender subcutaneous nodules under the skin and plaque-like lesions are also common. Erythema nodosum, characterized by painful nodules on the lower legs (shins), is frequently seen in sarcoidosis. This condition can sometimes show up years after an injury or getting a tattoo. Eye problems, such as uveitis, are observed in about half of the patients. Significant heart issues, including heart block and sudden death, can occur in sarcoidosis, and in some instances, it's suggested to have a cardioverter-defibrillator implanted for preventive measures. Central nervous system (CNS) outcomes can involve diabetes insipidus and an increase in the hormone prolactin (hyperprolactinemia). Those with severe symptoms tend to have a lower quality of life and often experience mental health issues, including depression and anxiety.

The types of tests that may be ordered to properly diagnose sarcoidosis include: - Laboratory tests to check for abnormal aspects of blood, liver function, and levels of different substances in the blood. This may include checking for signs of anemia, leukopenia, thrombocytopenia, and measuring blood urea nitrogen, creatinine, glucose, electrolytes, and serum calcium. - Imaging scans such as chest x-ray, CT scan of the chest, MRI, or PET scan to assess the extent of the disease and check for involvement of other organs. - Pulmonary function tests to measure lung function, including DLCO and breathing patterns. - Biopsy, such as a transbronchial biopsy or mediastinoscopy, to confirm the presence of noncaseating granulomas and rule out other conditions. - Regular imaging tests and lung function tests for patients without symptoms to monitor the condition. - Medications may be considered for symptomatic or progressive cases, including oral glucocorticoids or alternative steroid-sparing agents. - In severe cases with end-stage lung disease, lung transplant may be an option.

The doctor needs to rule out the following conditions when diagnosing Sarcoidosis: - Tuberculosis - Cat scratch disease - Lung cancer - Lymphoma - Occupational lung disease - Fungal infection

A pulmonologist or a rheumatologist.

In the United States, the chance of getting this disease in your lifetime is about 2.4%.

Sarcoidosis is often a condition that does not require treatment, as it often shows no symptoms and does not worsen over time. However, in cases where symptoms worsen or the disease progresses, medications called oral glucocorticoids can be used to control inflammation in the lungs. If glucocorticoids are not an option, alternative medications known as steroid-sparing agents can be considered. In severe cases of lung damage, a lung transplant may be an option, although this is a major surgery with its own risks and requires lifelong immunosuppressive therapy.

Sarcoidosis is a disease that can affect multiple parts of the body, creating small, benign lumps called noncaseating granulomas in different organs.

Granulomatous Disease Inflammatory Disorders Lung Disease Lung Disease & Respiratory Health Sarcoidosis