What is it?
Sarcoidosis is an inflammatory disease that causes the formation of clumps of cells in the organs, preferentially in the lungs. It is also referred to as the Besnier-Boeck-Schaumann disease or by the acronym BBS. Its origin is unknown. Except in its severe and fatal form (less than 5% of cases), sarcoidosis heals spontaneously and does not reduce the life expectancy of the affected individual. Sarcoidosis is considered a rare but not exceptional disease. Its exact prevalence is unknown because the disease is not always associated with symptoms, but it is estimated that 1 in 5,000 to 1 in 20,000 people is affected in the total population. 6,000 to 12,000 new cases are diagnosed annually in France.
Symptoms of Sarcoidosis
The clusters of inflammatory cells called “granulomas” can potentially affect many organs: the skin, the eyes, the heart, the nervous system, the kidneys … The sarcoidosis can take very different forms, depending on its extent: it can be completely asymptomatic (which explains that not all cases are undiagnosed), and touch one or more organs.
Sarcoidosis often causes fatigue, fever, weight loss and muscle and joint pain. In addition to these general signs, there are symptoms of organ damage in particular: persistent cough and shortness of breath associated with lung damage are the most common signs, as are skin lesions, ocular and cardiac arrhythmia.
There are two distinct forms:
- An acute but benign form, corresponding to Löfgren’s syndrome. It results in fever, joint pain and the appearance of inflammation in the legs (erythema). The healing is spontaneous and takes from a few weeks to a few months.
- The disease can progress, but rarely, in chronic form and last for several years (usually 5 to 15 years).
The origins of the disease
The causes of sarcoidosis are still unknown. Current knowledge points to a disruption of the immune system leading to its overreaction to an unidentified foreign aggressor. It could be an environmental allergenic substance or a bacterium. This immune abnormality would have a genetic cause.
Risk factors for Sarcoidosis
Sarcoidosis appears preferentially in young adults aged 25 to 45, both men and women. It is neither contagious nor hereditary. Family forms develop, however, in very rare cases (suggesting, again, a genetic factor). Researchers fail to explain why this disease is much more prevalent in black people and in more severe forms. Neither lifestyle nor the environment seems to be risk factors.
Prevention and treatment of Sarcoidosis
In the absence of knowledge of the causes of the disease, the symptoms of the disease are treated. The treatments consist in preventing the appearance of pulmonary fibrosis (the main risk for the patient) and in treating the possible complications (the attacks of the heart, the brain, the kidneys and the eyes) with anti-inflammatory drugs not steroids (corticosteroids). When corticosteroids are powerless, immunosuppressants are prescribed.
Remember that often the disease heals spontaneously after two or three years, in 30 to 70% of cases. Sarcoidosis is lethal only in its severe form, ie 0.5 to 5% of cases, most often by pulmonary fibrosis and to a lesser extent by cardiac involvement. People undergoing early and adapted treatment have a life expectancy equal to that of the rest of the population. However, we must not neglect the psychological consequences of the disease in young people who have it.