Sarcoidosis is a multisystem disorder of unknown cause which can affect any organ of the body taking the form of cells which cluster together in tiny nodules, or sarcoid granulomas. These are clusters of chronic inflammatory cells.
Sarcoidosis can develop in almost any organ. Most commonly it attacks the lungs, eyes, skin, more rarely the brain and nervous system. It can also spread to other organs such as the liver, heart and kidneys. The disease can range from a mild, self-limiting condition which needs no treatment, to a severe, chronically progressive illness. Children usually recover from sarcoidosis, but this may take some years.
What are the symptoms?
Initially, most affected persons have symptoms of fever, fatigue and weight loss. Other common symptoms include chronic cough, swelling of the lymph glands, skin rash, shortness of breath, fatigue, joint pains and swelling and hypertension (high blood pressure). Indeed, sarcoidosis can cause almost any combination of symptoms and signs.
Although Sarcoidosis usually affects adults in the age range 20-40, children (rarely) and elderly persons can be affected. Research so far has identified a higher rate of occurrence in the following racial groups: the black population in the United States and the Caribbean regions, Scandinavians, Puerto Ricans, Irish and Japanese. It is more common in women than men.
Sarcoidosis may mimic many other diseases such as Lupus, Chronic Fatigue syndrome/Myalgic Encephalomyelitis, Tuberculosis and Arthritis (see entries). It may also be a chance finding, for example on a chest X-ray done for another reason.
What are the causes?
Diagnosis is usually by exclusion as the cause has not yet been identified.
Sarcoid granulomas result from chronic inflammation. The acute inflammatory response to an infection is usually beneficial, walling off the infection in order to contain and destroy it. If the infection persists despite the body’s response, then the chronic build up of inflammatory cells may lead to granuloma formation. An example of this is Tuberculosis. It must be stressed that although sarcoid granulomas look like a response to chronic infection, no causative germ or virus has been found.
How is it treated?
The majority of patients recover without treatment and many do not have relapses. In the most severe cases the disease can be life threatening. Some affected people do need medication and for these individuals steroids can be effective usually given directly; for example, eye drops for eye symptoms. However, a course of steroid tablets may be needed.
There are clearly genetic factors which are important. How genes interact with other factors to produce Sarcoidosis is not known.
None. Sarcoidosis is not known to occur before birth.