Sarcoidosis is a rare inflammatory condition in which chronic lesions called granulomas are formed and can affect almost any organ or system resulting in functional and structural abnormalities. In ninety percent of the cases, it involves one or both lungs in a condition known as pulmonary sarcoidosis. Granulomas can turn into scar tissue if left untreated. Other organs affected include heart, kidneys, liver, eyes, skin, and some other areas.
Sarcoidosis was first explained by an English doctor named Jonathan Hutchinson hence this condition was previously known as Hutchinson’s disease.
Cause and Risk Factors
There is no established cause of sarcoidosis. However, experts believe but haven’t yet proved that a certain change in the genes result in the overreaction of body cells that recruit other cells responsible for inflammation.
The exaggerated immune response seen in this condition could also be triggered by bacteria or chemicals.
Signs and Symptoms
Generally, signs and symptoms of sarcoidosis depend on the affected system.
- High fever
- Inflamed joints which are painful
- Enlarged lymph nodes
- Erythema nodusum: Reddish and painful lumps commonly seen on anterior part of legs
- Weight loss
- Visual disturbances
Pulmonary sarcoidosis that affect the lungs have an additional set of signs and symptoms:
- Dry chronic cough
- Shortness of breath usually associated with pain
- Easily fatigued
- Chest tightness and pain
As lungs are the organs most frequently affected, hence following complications are quite common:
- Pulmonary Fibrosis: The granulomas can undergo fibrosis and convert into scar tissue. Scarring of the lungs will deprive them of functional exchange of air. Over time, it can lead to shortness of breath and low oxygen levels in the blood.
- Pulmonary Hypertension: Scar tissue can obstruct arteries present in the lungs resulting in high blood pressure as the heart will perform forceful contractions to pump blood in the vessels.
Complications involving other organs are:
- Dry Eye Syndrome: Chronic inflammation can block the tear ducts hence leading to drying of the eyes.
- Glaucoma & Cataracts: Occurs rarely when sarcoidosis is left untreated
- Heart Complications: Irregular heartbeats, heart block, heart failure and pericarditis can occur when sarcoidosis affects the heart.
- Hypercalcemia & Hypercalciuria: High levels of calcium in the blood and urine can occur which can also lead to kidney stones and failure.
- Sinusitis: Chronic inflammation of the sinuses of the nose can happen where it causes runny and stuffy nose along with headache.
Diagnosing sarcoidosis can be challenging and may require a number of different tests and investigations.
- Radiological Tests: X-ray and CT scan of the chest can provide a basic differential diagnosis of pulmonary sarcoidosis but may need further investigation. MRI and PET scan is required to look into other affected organs such as brain and heart.
- Lung/Pulmonary Functional Tests (PFTs): To look for abnormal lung function
- Lung Biopsy: Performed in case when scarring of lung tissue is suspected. A bronchoscope is inserted via mouth or nose into the lungs and airways and specimen are taken for laboratory tests.
- Electrocardiogram (ECG/EKG): To check for irregular heartbeat
- Blood Tests: It can reveal high calcium, vitamin D and enzyme levels which are increased in sarcoidosis. However, it cannot be used for diagnosis as these can be increased in other conditions as well.
Treatment is mostly focused on controlling the symptoms and preventing complications.
- Corticosteroids: They are used to suppress and reverse inflammation over a period of several months. Prednisolone is the most common steroid used for this purpose. Side effects such as weight gain, acne, reduced sleep and unstable moods can occur with corticosteroids.
- Immunosuppresive Therapy: These drugs control the over-reactive immune response seen in sarcoidosis. Drugs such as methotrexate (MTX), CellCept and azathioprine are commonly employed.
- Antimalarials: It has been found that chloroquine and hydroxychloroquine, drugs used for malaria, can reduce high calcium levels in the blood and also manage skin manifestations seen in sarcoidosis.