SARCOIDOSIS

What is it?

Sarcoidosis, or sarcoid as it is sometimes known, is a condition which can affect any part of the body, but most commonly it affects the lungs, skin, and eyes. It appears in various forms, sometimes producing symptoms in only one part of the body, sometimes in many parts at the same time.

Who gets it?

Sarcoidosis can occur at all ages but is most frequent in young adults and rare in children. Its cause is unknown. One theory is that it may be a very unusual type of infection, but not of the kind that can be caught from a person who has it. There is much research going on at the moment in an attempt to find the cause.

What are the symptoms?

These are very variable. Often it starts fairly abruptly with the person affected feeling poorly and perhaps having a fever, joint pains or, as often happens, painful red lumps on the shins. The eyes may be sore and vision is sometimes blurred. The lymph glands may enlarge, and can be felt as small lumps in the neck, armpits or groin. Lymph glands in the chest next to the lungs are also very commonly enlarged, although this causes no symptoms and can only be detected on a chest x-ray.

The lung itself is often affected without producing any symptoms, although sometimes breathlessness and a dry cough can occur. Indeed in some people, especially older adults, this may be the only symptom of the condition. Occasionally chemicals in the blood may be affected, with an increase in the amount of calcium being the most common change.

What tests will the Doctor want to do?

A chest x-ray is nearly always performed to examine the general condition of the lung tissue and, in particular, to look for the presence of large glands. Blood tests are usually performed, and special breathing exercises may be done to see how the lungs are working.

Areas affected by sarcoid have a characteristic appearance when looked at under the microscope, so a small specimen (a biopsy) is often the best way to make sure of the diagnosis. When the lungs are involved, a bronchoscopy may be performed. A narrow flexible telescope is passed via the nose down the windpipe into the lungs and a biopsy is taken. The test is simple, safe, and painless, and is usually performed with a local anaesthetic and simple sedatives.

In some cases sarcoidosis can be diagnosed with a special skin test, but this can take four to six weeks to give an answer.

What is the treatment?

Steroids work extremely well, and are virtually the only treatment which is effective. In some situations they can be given directly to the area from which the symptoms originate (for example, eye drops for eye symptoms), but usually tablet treatment is required.

Steroids may have side-effects if used in high doses over a long period of time, so treatment usually comprises only a short period of a high dose of tablets, followed by a longer period on a much safer, low dose. If steroids are stopped too soon, the sarcoid may come back and cause more scarring. It is usually necessary to continue treatment for twelve months or more before stopping.