Understanding sarcoidosis
Sarcoidosis is a chronic inflammatory disorder characterised by the formation of granulomas in different body tissues. Granulomas are clusters of inflammatory white blood cells that form non-cancerous nodules and may interfere with normal tissue function.
Organs commonly affected by sarcoidosis
Although sarcoidosis is often a systemic condition, it can also be limited to one organ. Commonly affected areas include the lungs, lymph nodes, eyes, joints and skin. The liver and nervous system may also be involved.
In rare cases, heart involvement can lead to cardiomyopathy, heart failure, fainting or abnormal heart rhythms.
When the nervous system is involved, symptoms may include:
Headaches
Confusion
Peripheral nerve tingling
Numbness and seizures
How common is sarcoidosis?
It is difficult to estimate how common sarcoidosis is because many people have no symptoms. Its prevalence in the general population is estimated at around 10–20 cases per 100,000 people.
Sarcoidosis most often develops between the ages of 20 and 40. It can occur in older people, but is rare in children and older adults. People of all racial and ethnic backgrounds can be affected. The cited source reports that sarcoidosis is three to four times more common among Black people and that the disease tends to be more severe in this group.
In most ethnic groups, women and men are affected at similar rates. Among Black people, women are reported to be twice as likely as men to develop sarcoidosis.
Main causes of sarcoidosis
The cause of sarcoidosis is unknown, although it is often described as an autoimmune disorder.
Environmental antigens are thought to trigger an immune response that leads to inflammatory granulomas, but specific triggers have not been established. Sarcoidosis is not an infectious disease, although a microbial agent such as a virus may trigger an exaggerated immune response.
Some occupational exposures have also been considered possible triggers. Following the September 11 attacks on the World Trade Center, several first responders developed granulomatous lung disease similar to sarcoidosis; this was thought to be associated with inhaling dust particles.
Common symptoms of sarcoidosis
Sarcoidosis can cause a wide range of symptoms. An estimated 30–40% of people with the disease have no symptoms. Some have disease limited to one area, while others have systemic or multisystem disease.
The most common complaints among people with symptoms involve the respiratory system:
Cough
Shortness of breath
Chest discomfort
Other possible problems include:
Skin changes, including nodules, plaque-like lesions and erythema nodosum (painful, red bumps, often on the legs)
Systemic symptoms such as fever, sweating, malaise, weight loss and fatigue
Joint and musculoskeletal pain
Eye inflammation, dryness or blurred vision
Swollen lymph nodes and salivary glands (parotid glands)
What findings may occur in people without symptoms?
More than 90% of people without symptoms are reported to have lung involvement that may be visible on a chest X-ray. They may have enlarged lymph nodes in the centre of the chest (hilar lymphadenopathy), with or without other lung findings. Liver-test abnormalities may also occur.
Treatment of sarcoidosis
Many cases of sarcoidosis resolve on their own. When the disease causes symptoms, treatment may be needed for a limited period or during flare-ups.
One study cited in the source article found that 43% of patients at a sarcoidosis clinic were receiving treatment five years after diagnosis. The article also reports that around 10% may need ongoing treatment to control chronic disease. It describes the overall prognosis as generally favourable and gives a mortality estimate of 1–5%; estimates can vary with the population and source.
Deciding who may need treatment
The decision depends on several factors:
The organs involved
The severity of symptoms
Whether the disease persists
The patient’s preferences
Medicines commonly used to treat sarcoidosis include corticosteroids such as prednisone; immunosuppressive medicines such as methotrexate, leflunomide, azathioprine and mycophenolate; and biological medicines such as adalimumab (Humira) and infliximab (Remicade). Treatment choices and risks must be discussed with the treating specialist.
Diagnosing sarcoidosis
Sarcoidosis can be difficult to diagnose because it can resemble other conditions. Tests may include a full clinical assessment, laboratory tests and imaging. A biopsy of affected tissue may be used to look for non-caseating granulomas. Lung assessment may include CT imaging, PET imaging and pulmonary-function tests to help evaluate the extent and severity of disease.
In closing
Many people with sarcoidosis do not need treatment, or need only short-term treatment for symptoms. Others have chronic disease that may continue for many years and can be serious. Diagnosis, monitoring and treatment should be managed by qualified health professionals.
Source: https://www.emedihealth.com/respiratory-health/lung-diseases/sarcoidosis