What is sarcoidosis?
Sarcoidosis is an inflammatory condition in which small clusters of immune cells, called granulomas, form in one or more organs. The lungs and the lymph nodes in the centre of the chest are involved in most patients, but the skin, eyes, heart, nerves, liver, kidneys and joints can also be affected.
Sarcoidosis is uncommon. It usually begins between the ages of 20 and 50 and occurs in both men and women. It is not an infection, it is not cancer, and it cannot be passed on to others.
Many people with sarcoidosis need no treatment at all, because the disease settles by itself within two to three years. Others have persistent or organ-threatening disease that needs careful long-term management. The key tasks are to confirm the diagnosis, to look for involvement of other organs, and to decide whether treatment is warranted.
Symptoms of sarcoidosis
Some patients have no symptoms and are diagnosed after a routine chest X-ray shows enlarged lymph nodes. When symptoms occur, they may include:
- Lung symptoms: dry cough, breathlessness on exertion and chest discomfort.
- General symptoms: fatigue, low-grade fever, night sweats and weight loss, which can closely resemble tuberculosis.
- Skin: tender red lumps on the shins (erythema nodosum), or raised patches on the face, nose or old scars.
- Eyes: redness, pain, blurred vision or sensitivity to light due to uveitis.
- Joints: pain and swelling, particularly around the ankles.
- Heart: palpitations, blackouts or breathlessness from rhythm disturbance, which is uncommon but important.
A combination of fever, erythema nodosum, ankle arthritis and enlarged chest lymph nodes, known as Lofgren's syndrome, usually has a good outlook.
Causes and risk factors
The cause of sarcoidosis is not known. It is thought to arise when a genetically susceptible person mounts an exaggerated immune response to an environmental trigger, which may be an inhaled dust, chemical or microbial material. It is more common in some families and some ethnic groups, and certain occupational exposures have been associated with it.
Exposure to beryllium can cause a disease that looks identical to sarcoidosis, and some medicines, including certain cancer immunotherapies, can produce sarcoid-like reactions. These are considered during assessment.
How sarcoidosis is diagnosed
Diagnosis requires three elements: a compatible clinical picture, evidence of non-caseating granulomas in tissue, and reasonable exclusion of other causes of granulomas. In India the most important alternative is tuberculosis, which can look very similar on X-ray, CT and even biopsy. Lymphoma and fungal infection must also be excluded.
| Test | What it shows |
|---|---|
| Chest X-ray and CT | Enlarged lymph nodes in the chest and the pattern of lung involvement |
| EBUS-TBNA | Needle samples from chest lymph nodes for granulomas, TB testing and exclusion of cancer |
| Bronchoscopy with lavage and biopsy | Lung tissue and fluid for granulomas, cell counts and infection testing |
| TB tests on tissue (culture, molecular tests) | Whether tuberculosis is present before steroids are considered |
| Lung function tests including DLCO | How much the lungs are affected, and a baseline for follow-up |
| Blood calcium, kidney and liver tests | Involvement of other organs and high calcium levels |
| Eye examination and ECG | Silent uveitis and possible heart involvement |
EBUS-TBNA is a minimally invasive day procedure that has become the preferred way to sample chest lymph nodes and has largely replaced surgical mediastinoscopy. If heart involvement is suspected, cardiac MRI or PET scanning is arranged with cardiology.
Sarcoidosis treatment
Treatment is offered when sarcoidosis causes troublesome symptoms, impairs lung function, or threatens an important organ such as the heart, eyes, nervous system or kidneys. The ERS clinical practice guideline supports a watch-and-wait approach for patients who are well and whose lung function is stable.
Corticosteroids
Oral prednisolone is the first-line treatment when therapy is needed. The aim is the lowest effective dose for the shortest necessary time, with protection for bones and monitoring of blood sugar, weight and blood pressure.
Steroid-sparing treatment
When disease relapses or steroids cause side effects, methotrexate is the usual second-line medicine, with azathioprine, mycophenolate or leflunomide as alternatives. Anti-TNF biologic therapy such as infliximab is used for severe or refractory disease. Because these drugs suppress immunity, latent TB is checked for before they are started.
Multidisciplinary care
Care is coordinated with ophthalmology, cardiology, dermatology, rheumatology and nephrology where those organs are involved. Patients with advanced lung fibrosis or pulmonary hypertension may need oxygen, pulmonary rehabilitation and, rarely, referral to a transplant centre.
Outlook and follow-up
The majority of patients improve or remain stable, and many go into lasting remission. A minority develop chronic disease or lung fibrosis. Follow-up with symptom review, lung function tests, blood tests and periodic eye checks is continued for at least a few years, as relapses can occur, especially after steroids are reduced.
Fatigue can persist even after the inflammation settles. Graded exercise, good sleep and attention to mood help, and avoiding calcium and vitamin D supplements unless prescribed is sensible, since sarcoidosis can raise calcium levels.
When to seek urgent care
Seek urgent medical attention for fainting or near-fainting, a very fast, slow or irregular heartbeat, chest pain, sudden loss or blurring of vision with a painful red eye, new weakness or numbness, severe headache, marked thirst with confusion (which may indicate high calcium), or rapidly worsening breathlessness.
Frequently asked questions
Is sarcoidosis the same as tuberculosis?
No. Both cause granulomas and can look alike on scans, but sarcoidosis is not an infection and is not contagious. Tissue samples are tested for TB before steroids are started, because treating TB with steroids alone can be dangerous, and treating sarcoidosis with anti-TB drugs does not help.
Does everyone with sarcoidosis need treatment?
No. Many patients, especially those with few symptoms and normal lung function, are monitored without treatment because the disease often settles on its own. Treatment is started when symptoms, lung function or organ involvement justify it.
Is sarcoidosis a type of cancer?
No. Sarcoidosis is an inflammatory disease. However, enlarged lymph nodes can also be caused by lymphoma or other cancers, which is why a biopsy is usually taken to confirm the diagnosis.
How long will I need steroids?
When steroids are needed, a typical course lasts several months to a year, with gradual reduction. If the disease relapses or long-term treatment is needed, a steroid-sparing medicine such as methotrexate is usually added.
Can sarcoidosis affect the heart?
Yes, in a small proportion of patients. Cardiac sarcoidosis can cause rhythm problems and needs specialist cardiology care. An ECG is part of the initial assessment, with further heart imaging when there are symptoms or abnormal results.
Can I become pregnant if I have sarcoidosis?
Most women with sarcoidosis have healthy pregnancies, and the disease often stays stable during pregnancy. Some medicines, such as methotrexate, must be stopped well before conception, so pregnancy should be planned with your doctors.
Related conditions and procedures
Consult Dr. Gogineni Ratnakara Rao
Apollo Hospitals, Financial District: Monday to Saturday, 8:30 AM to 5:00 PM. Anything in Lung Clinic, Chanda Nagar: Monday to Saturday (Thursday closed), 6:00 PM to 9:00 PM.