Sarcoidosis Dr Rob Hicks Sarcoidosis is one of those conditions that cause the body to attack itself. It can result in breathlessness, blurred vision, painful joints and a general loss of wellbeing. But for most people a full recovery is likely.

In this article

What causes it? What are the symptoms?

Who's affected? How's it diagnosed?

What's the treatment?

Sarcoidosis is believed to be one of the autoimmune diseases where the body attacks itself. Why this happens isn't clear, but infection often precedes the first signs of the disease.

In sarcoidosis, commonly referred to simply as 'sarcoid', areas of inflammation may appear on the body. Any part of the body can be affected but the most commonly affected areas are the lungs, skin, eyes and lymph nodes. One area alone may be affected, or many at once.

As with many diseases, sarcoidosis is often present without causing any symptoms. When symptoms do appear, however, they either do so abruptly (acute sarcoidosis), or gradually over a number of years (chronic sarcoidosis).

Acute sarcoidosis brings with it fever, cough, joint pains and tiredness, and makes people feel generally unwell. Red and tender lumps usually appear on the shins (called erythema nodosum) and if the eyes are affected they become red and vision becomes blurred. Lymph nodes enlarge and are also tender.

Over the years, chronic sarcoidosis causes coughing and shortness of breath as the lungs become more and more inflamed and their ability to function deteriorates. The eyes and shins may also be affected in the same way as in acute sarcoidosis.

Although it may occur at any age, young adults are far more likely to develop sarcoidosis. It sometimes runs in families and those of Afro-Caribbean descent are more likely to be affected.

Diagnosis of sarcoidosis isn't always easy, as many other conditions cause similar symptoms. Often it's only discovered when an x-ray of the chest reveals the characteristic swollen lymph nodes or shadowing in the lungs. Examining a sample of tissue taken from affected skin or lung under the microscope is an accurate way of confirming the diagnosis.

Since the lungs are commonly affected, tests to assess lung function are usually performed. Sarcoidosis can also cause the level of calcium in the blood to rise, so this may be measured too.

Currently, there's no cure for sarcoidosis. For one in ten people the disease slowly gets worse over time and for one in 50 it proves fatal. However, for the majority of those with the disorder - around eight out of every ten people, in fact - the condition resolves spontaneously after a few years and never comes back.

Relief from symptoms can be found with painkillers, and steroids can also prove extremely effective. When used to treat chronic sarcoidosis, steroids may need to be used at a low dose for many months, sometimes a year or more. During this time, regular blood and lung function tests and chest x-rays are performed to monitor how well the treatment is working.

This article was last medically reviewed by Dr Rob Hicks in July 2006.