Sarcoidosis

Sarcoidosis is a disease characterized by inflammatory lumps or nodules (granulomas) in one or more organs of the body.

A granuloma is a collection of cells created when the immune system attempts to isolate a foreign substance that it is otherwise unable to eliminate.

Sarcoidosis can affect almost any organ in the body, but mostly the lungs and lymph glands. It can also affect other parts of the body, such as the skin, the eyes, the liver, the kidneys, the nerves, etc.

Sarcoidosis is defined as a multisystem granulomatous disease of autoimmune nature and unknown origin.

Although sarcoidosis is a benign disease, if a granuloma severely affect an organ, it can prevent the organ from working properly and have a serious impact on the health of the patient.

Sarcoidosis is a disease of unknown cause. It may have a possible autoimmune origin since granulomas are primarily made up of cells of the immune system (macrophages and lymphocytes).

It is also believed that environmental factors may trigger the immune response, for example, the exposure to some toxic or infectious material.

Besides, a genetic cause is also suggested because it is usually noted in family groups.

The incidence of the disease is very variable. It depends on the country, but the reason for the difference is still unclear.

It is estimated an overall prevalence of 5-40 cases per 100,000 inhabitants per year.

It has a slightly higher incidence in women than in men. The average age of diagnosis is around 20-40 years, with a second peak of incidence in women around 60 years old.

Sarcoidosis may sometimes go unnoticed without any associated symptoms. In many cases, however, the disease starts with nonspecific symptoms such as:

• Weakness
• Dry cough
• Chest pain, usually in the breastbone (sternum).
• Shortness of breath while exercising
• Fever
• Loss of appetite and weight loss

As previously noted, almost any part of the body can be affected. Nevertheless, the following ones are the most common signs and symptoms:

• Lung involvement: It is very common. It is present in more than 90% of the cases. It is seen as a persistent dry cough, dyspnea (shortness of breath) on exertion, pleural effusion, etc.
• Eye disorders: They are present in 25-50% of the cases. The eyes become red and teary. Symptoms also include vision blurry or photophobia usually due to anterior uveitis.
• Skin lesions: Tender reddish bumps or patches often appear on the face or joints. Erythema nodosum is a common presentation of the disease. Lupus pernio is less common, but is typical of sarcoidosis.
• Hepatomegaly: Enlarged liver and painful on palpation.
• Arthralgia and arthritis: Joint pain and inflammation.
• Adenopathies: Enlarged lymph nodes (located in the armpits, groin, neck, etc.)
• Kidney stones: Due to changes in calcium metabolism.
• Heart problems: Arrhythmia, pericarditis or heart failure.
• Neurological disorders: Hearing loss, meningitis, seizures, psychiatric disorders, etc.

When the disease is suspected, it can be confirmed by:

• Chest X-ray, CT, bronchoscopy, and other diagnostic tests where an abnormal result point out a possible sarcoidosis.
• Biopsy of the granulomas.

In the past, this disease used to be confused with tuberculosis since the nodules that are frequently found in the lungs resemble the nodules of a tuberculosis infection.

Treatment is based on the administration of corticosteroids for 1 or 2 years. Corticosteroids may slow down the course of the disease and may even cure it, although some authors argue that the disease cures itself without the use of corticosteroids. Therefore, the prescription of corticosteroids should be evaluated carefully and reserved only for severe cases. Corticosteroids can cause weight gain as a side effect.

If there is no clinical improvement, drugs that suppress the immune system (immunosuppressive drugs) and decrease the aggressiveness of the disease, may be needed. Unfortunately, they increase the susceptibility to infections (e.g. tuberculosis) and tumors due to a decrease in the immunity.

There are rare cases, when the lungs are severely affected, where a lung transplantation is needed.

The prognosis of the disease is quite good. About 60 or 70% of the time, sarcoidosis cures itself in one or two years without consequences.

In about 20 or 30% of cases, there may be a permanent damage to the lungs.

Only 15 or 20% of all patients develop a chronic and relapsing form of sarcoidosis.

Death can be blamed on sarcoidosis only in about 1-10% of cases. The most common causes are due to respiratory failure and massive or recurrent hemoptysis (coughing up blood).