Sarcoidosis. The name itself does not give anything away. The name does not explain what sarcoidosis is, what it does and who is affected by it. If you ever heard the word ‘sarcoidosis’ and wondered what it is, you can find that information below.

What is sarcoidosis?

Sarcoidosis is characterised by the formation and presence of noncaseating granulomas.¹ 

A granuloma is a collection of different immune cells which clump together to form a solid mass. A noncaseating granuloma is a granuloma that does not contain any dead cells.^1,2

These noncaseating granulomas can appear in many different organs. As a result, the presence of these granulomas will interfere with the function of these organs to some extent. For some people, the granulomas only lead to minor impairments of the affected organ or organs which do not cause any symptoms. In the more serious cases, the granulomas lead to the severe dysfunction of one or several organs which can prove fatal.^1,3

Generally, sarcoidosis has one of two outcomes. In some cases, it eventually goes away, usually within 1 to 3 years. On other occasions, it becomes a chronic (ongoing long-term) disease.³

The cause of sarcoidosis is still unknown. It is suspected that a combination of certain genes and environmental factors (things we eat, chemicals we are exposed to and so on) contributes to the appearance of sarcoidosis.¹

Who is affected by sarcoidosis?

Sarcoidosis can be found in people of all ethnicities and ages. However there are people of certain ethnicities and ages that are affected more frequently.^1,3

Scandinavians and African Americans tend to suffer from sarcoidosis more often than other ethnicities. Furthermore, sarcoidosis is more common in people between 35 and 50 years of age.^1,3

Additionally, sarcoidosis is seen more frequently in people assigned female at birth than in people assigned male at birth. This is especially true among the African American population.¹

Types of sarcoidosis

As the title suggests, there are many different types of sarcoidosis. Most types of sarcoidosis are named after the organ they are affecting. For example, sarcoidosis of the lungs is called pulmonary sarcoidosis while sarcoidosis in the kidneys is called renal sarcoidosis.¹

Lungs (pulmonary sarcoidosis)

Affecting more than 90% of sarcoidosis patients, pulmonary sarcoidosis is by far the most common type of sarcoidosis. It results in the formation of granulomas in the lungs and lymph nodes in the chest.¹

Pulmonary sarcoidosis is divided into stages 1-4, from mild to severe. About 50% of people with stage 1 pulmonary sarcoidosis are asymptomatic ( have no symptoms). Stage 1 pulmonary sarcoidosis is also by far more likely to simply vanish at some point. The higher the stage, the more likely it is that pulmonary sarcoidosis will become a chronic illness with the corresponding symptoms.¹

Common symptoms of pulmonary sarcoidosis are:³

• Coughing
• Pain in the chest
• Shortness of breath (dyspnea)

Löfgren’s Syndrome (LS) is also a type of sarcoidosis. LS is mostly found in Caucasians from Europe, especially those who hail from Sweden and the Netherlands.³  

Löfgren’s Syndrome

LS often causes:³

• Fever
• Swollen lymph nodes in a certain part of the lung (bilateral hilar lymphadenopathy)
• Painful skin rashes (erythema nodosum)
• Painful inflammation of the ankles (bilateral ankle arthritis)

Sarcoidosis affects the joints, bones and the heart muscle

Joints (sarcoid arthropathy)

Sarcoid arthropathy regularly leads to the painful inflammation of several joints (polyarthritis), often involving the ankles.³

Bone (Bone sarcoidosis)

Bone sarcoidosis causes damage to bones. Despite that, bone sarcoidosis does not result in any symptoms in roughly 50% of cases. Symptoms with this form of sarcoidosis only tend to arise if the bones of the hand are affected. Symptoms are usually:³

• Swollen fingers (dactylitis)
• Pain in any part of the hand

Heart muscle (sarcoid myopathy)

Sarcoid myopathy targets the heart muscle and is asymptomatic in most cases. Occasionally it may present with severe symptoms.³

Skin (cutaneous sarcoidosis)

Cutaneous sarcoidosis is the second or third most common type of sarcoidosis. The skin manifestations of sarcoidosis(skin lesions) are often the first sign of sarcoidosis. In some cases, these skin lesions remain the only signs of sarcoidosis.³ 

The skin lesions brought on by cutaneous sarcoidosis tend to be asymptomatic. Unfortunately, they can still be annoying for a different reason. These skin lesions can be quite unpleasant to look at which can be a cosmetic problem. This is especially true if these skin lesions appear on the face.³

Common skin lesions and conditions of cutaneous sarcoidosis include:³

• Solid, small bumps of various colours (papules)
• Slightly larger lesions of various colours (plaques)
• Solid, small bumps originating in the deeper layers of the skin (subcutaneous nodules) 
• Slightly larger lesions of various colours on the head and the neck (lupus pernio)

Eyes (ocular sarcoidosis)

Ocular sarcoidosis can impact any part of the eye. The most commonly affected parts are:³

• Uvea (middle part of the eye)
• Tear glands
• Conjunctiva (thin layer covering the white of the eyes and the eyelids)

Sometimes, these eye-related conditions are the only sign that a person has sarcoidosis. Initially, these conditions do not tend to cause any problems. When they do, they can result in impaired eyesight.³

Liver (hepatic sarcoidosis)

Hepatic sarcoidosis is asymptomatic in some cases. On other occasions, it can cause inflammation of the liver. If this inflammation goes on for too long, it can potentially result in liver damage and scarring (cirrhosis).³ 

Depending on the extent the liver is affected, typical signs and symptoms include:³

• Extreme tiredness (fatigue)
• Enlarged liver (hepatomegaly)
• Fever
• Abdominal pain (on the upper right side where the liver is located) combined with itchy skin (pruritus)
• Skin and the white of the eyes turning yellow (jaundice)
• Weight loss
• Restricted blood flow into the liver (portal hypertension)

Spleen (splenic sarcoidosis)

Splenic sarcoidosis can cause an enlargement of the spleen (splenomegaly) and general/constitutional symptoms.³

Examples of such symptoms are:³

• Extreme tiredness (fatigue)
• Fever
• Weight loss

Oesophagus, stomach and intestine (digestive tract sarcoidosis)

Digestive tract sarcoidosis is very rare. This type of sarcoidosis gives rise to large lesions in the digestive tract, most frequently in the stomach and parts of the intestine.³ 

Possible signs and symptoms are:³

• Nausea and vomiting
• Abdominal pain
• Weight loss
• Blocked digestive tract(intestinal obstruction)
• Bleeding in the digestive tract
• Loss of too much protein in the digestive tract (protein-losing enteropathy)

Heart (cardiac sarcoidosis)

Cardiac sarcoidosis tends to affect certain parts of the heart more often than others. Nevertheless, it can develop in any part of the heart. People with cardiac sarcoidosis are asymptomatic for the most part. In the cases where they are not, the common signs and symptoms are:³

• Shortness of breath (dyspnea)
• Awareness of heartbeat(palpitations)
• Chest pain
• Irregular heartbeat (arrhythmia)
• Heart disease (cardiomyopathy)
• The heart is no longer able to pump enough blood (congestive heart failure)

Nervous system (neurosarcoidosis)

Neurosarcoidosis is rather rare. It can impair the function of nerves in the brain, the spinal cord and the rest of the body. Often, nerves in different parts of the body are affected at the same time. Neurosarcoidosis can cause:³

• Sudden weakness of the facial muscles (facial palsy)
• Hearing loss
• A buildup of liquid and thereby pressure in the brain (hydrocephalus)
• Seizures
• Nerve damage in places other than the brain and spinal cord (peripheral neuropathy)

Kidneys (renal sarcoidosis)

Renal sarcoidosis is fairly rare. It mostly manifests as granulomatous interstitial nephritis (an inflammation in the kidneys caused by granulomas) and reduced kidney function. The latter can result in the presence of increased levels of immune cells and protein in the urine.³ 

Sarcoidosis affecting various parts of the head and throat

Sarcoidosis can compromise the function of the larynx (voice box), the salivary glands, the nose and the sinuses. Impaired salivary glands tend to cause far fewer problems than dysfunction of the larynx, the nose and the sinuses.³

Sarcoidosis affecting the larynx (laryngeal sarcoidosis) and nose and sinuses (sinonasal sarcoidosis) can lead to:³

• Blocked nose
• Runny nose (rhinorrhea)
• Inability to smell anything (anosmia)
• Hoarseness
• Shortness of breath (dyspnea)
• Struggling to swallow things (dysphagia) 

Summary

Sarcoidosis is a disease of unknown origin. It is believed to be caused by a mixture of certain genes and exposure to specific elements of our environment. Sarcoidosis leads to the formation of granulomas. Granulomas consist of immune cells which form solid masses by sticking to each other. These granulomas can impair the function of one or many parts of the body. The extent of that impairment strongly differs from person to person. In general, sarcoidosis is seen most often in African-American and Scandinavian people. Almost all the different types of sarcoidosis are named after the organs they affect. Each of these sarcoidosis types tends to come with its own set of conditions and symptoms although there can be a certain overlap. Sarcoidosis can impact the lungs, heart, eyes, liver, spleen, kidneys and various other parts of the body.