Sarcoidosis: Causes, symptoms, and treatment
While sarcoidosis can occur in any organ, an estimated 90 percent of cases involve the lungs.
Currently, there is no cure for sarcoidosis, although some cases resolve without medical intervention.
Granulomas can damage organs and may require treatment. This may be the case if they begin to take up a significant portion of an organ or persist for a long time.
This article looks at the causes and symptoms of sarcoidosis and explores how they may be treated.
What is sarcoidosis?
While sarcoidosis can occur in any organ, it occurs most commonly in the lungs.
Sarcoidosis is a chronic inflammatory condition that leads to the formation of persistent granulomas or clumps of inflammatory cells.
Granulomas are formed as a normal part of the immune response, but they typically break up after foreign objects or irritants have been expelled.
Sarcoidosis involves the development of granulomas that form or linger when they are no longer needed.
Researchers are still not sure why or how sarcoidosis occurs. However, it may be the result of an excessive immune response to an irritant or allergens, such as:
There is some evidence to suggest certain individuals may be more genetically predisposed to develop the condition.
The bulk of sarcoidosis cases involve or begin in the lungs. The lymph nodes and glands, especially those surrounding the lungs, are also impacted. However, sarcoidosis can affect any organ in the body.
Though less common, cases involving organs, such as the heart, brain, and kidneys, are often far more severe. Also, they can be difficult to treat and may cause serious health complications.
An estimated 10-15 in 100,000 Americans develop sarcoidosis annually.
However, the actual risk of developing the condition varies, largely depending on individual factors. These include:
- Race and/or ethnicity: Rates of sarcoidosis among African-Americans are estimated to be three to four times higher than white people.
- Age: Sarcoidosis most commonly impacts those between 20 and 40 years of age.
- Sex: As with most inflammatory conditions, women are considered at greater risk of developing sarcoidosis, especially over the age of 50.
- Family history: Those who have family members who have had sarcoidosis are at a greater risk of developing the condition.
Further research is needed to better understand the association between race and ethnicity and sarcoidosis.
The symptoms associated with sarcoidosis can differ drastically between individuals.
Symptoms also vary greatly depending on the location of granulomas and the size of the organ involved.
In acute sarcoidosis, symptoms are present for less than 2 years, and half of those affected by them will have no symptoms after that.
In chronic cases, symptoms progress, linger or recur for weeks or years. The concern with chronic sarcoidosis is the progression from the granulomas to fibrosis in organs, such as in the lungs.
Noticeable symptoms only occur when granulomas have become invasive, accounting for a sizeable portion of the organ they are in. The development of symptoms also means that granulomas begin to impede or lessen the functioning of the organ.
Some of the signs and symptoms of sarcoidosis include:
- pain in the joints
- weight loss
- shortness of breath
- abnormal heartbeat
- abnormal sweating
Rashes can also develop on the lower extremities, such as ankles and shins, or on the upper body.
More specific signs may indicate which organ is involved. Symptoms associated with sarcoidosis in specific organs are detailed below.
Symptoms of sarcoidosis in the lungs include:
- chronic dry cough
- shallow breath or dyspnea - a shortness of breath or trouble catching the breath
- unidentifiable chest pain, often radiating out
Symptoms include a sore throat and swollen lymph nodes.
Symptoms of sarcoidosis in the lymphatic system include:
- swelling or edema, excess buildup of fluid
- difficulty swallowing
- sore throat
- general exhaustion or discomfort
Symptoms of sarcoidosis in the heart include:
- pain, often radiating throughout the chest
- feeling faint or fainting
- unexplained exhaustion
- palpitations with rapid, fluttering heart beat
- arrhythmias or irregular heartbeat
- edema or swelling caused by the build up of fluid
- dyspnea or shortness of breath and/or difficulty catching breath
Cases of sarcoidosis that impact the eyes do not often cause symptoms. This means many go undiagnosed until permanent damage has been done.
When present, the symptoms of sarcoidosis of the eye include:
- pain or soreness
- sensitivity to light
- blurred or cloudy vision
Symptoms of sarcoidosis of the nervous system include:
- facial paralysis or loss of muscle control
- inflammation in the brain, leading to seizures and other changes
- meningitis symptoms, such as headache and neck stiffness
- damage to small nerves
Symptoms of sarcoidosis of the skin include:
- erythema nodosum, which is a raised red rash on the shins and ankles, often warm and tender to touch
- nodules or growths under the skin, especially around scar tissue
- skin discoloration, where some regions become lighter or darker than normal
- lesions or sores, leading to permanent skin damage and disfigurement, often on the cheeks, nose, and ears
Joints, connective tissues, bones, and muscles
- loss of muscle control, tone, or function
- loss of flexibility, ease, or range of motion
- generalized joint pain
- generalized weakness and exhaustion
Recognizing the signs of sarcoidosis can be difficult.
Some 90 percent of all cases are not significant enough for doctors to be able to diagnose them. They may also be undetectable by radiographic devices.
Diagnoses are often made during examinations or testing for other health conditions, for example, chest X-rays for:
If sarcoidosis is suspected, a doctor will begin by examining the impacted area and reviewing a person's medical history.
Additional tests used to diagnose sarcoidosis include:
- computerized tomography (CT) scan
- positron emission tomography (PET) scan
- chest X-ray to assess lymph node involvement and lung damage
- lung function tests to assess lung volume or blood flow and associated oxygen delivery
- examinations of the eyes
- blood tests to assess organ function or change, in particular, measuring kidney enzymes and markers
- biopsies of organ tissues
Treatment and outlook
Anti-inflammatory medications can help reduce the symptoms of sarcoidosis.
In approximately half of all sarcoidosis cases, symptoms resolve or go away on their own.
More severe or persistent symptoms benefit from medical treatment. Though there is currently no cure for sarcoidosis, therapeutic options exist to treat the symptoms.
Some of the medications and therapeutic options available include:
- anti-inflammatory, topical or oral corticosteroids
- hydroxychloroquine (Plaquenil)
- tumor necrosis factor-alpha (TNF-alpha)
It is important that sarcoidosis is treated correctly as complications associated with long-term cases can include:
- heart conditions
- breathing difficulties
- kidney damage or failure
- muscle paralysis
- skin disfiguration and discoloration