Sarcoidosis is a medical condition characterized by inflammation associated with formation of specific nodules in multiple organs. These nodules comprise inflammatory cells and are known under the name granulomas. In the majority of patients granulomas form inside the lungs or lymph nodes although other organs and organ systems may be affected as well.
Classification of Sarcoidosis
There are various types of sarcoidosis. Annular sarcoidosis is the type affecting the skin. There are papular skin lesions organized in a typical annular pattern. Erythrodermic sarcoidosis and ulcerative sarcoidosis are also cutaneous form of the disease. They are rather rare. One more type of sarcoidosis affecting the skin is ichthyosiform sarcoidosis. The skin changes in this form of the disease look like the ones that develop in ichthyosis vulgaris. Hypopigmentated sarcoidosis leads to hypopigmentation of the affected skin. It is typical for dark-skinned individuals.
Furthermore, mucosal sarcoidosis leads to formation of pinhead-sized papules. Papules are also present in case of papular sarcoidosis while scar sarcoidosis, as the name suggests leads to skin scarring. Subcutaneous form affects subcutaneous tissue and leads to formation of deep-seated nodules.
Löfgren syndrome is relatively rare form of sarcoidosis affecting only specific ethnic groups such as Scandinavian people. Lupus pernio is characterized by indurated skin lesions predominantly affecting the ears, nose, lips or cheeks. This form resembles lupus vulgaris but is pathohistologically different.
Morpheaform sarcoidosis is relatively rare causing severe fibrosis and cutaneous skin lesions. Neurofibromatosis affects the central nervous system. This form is commonly associated with sarcoidosis of other organs and rarely occurs alone.
And finally, there is systemic sarcoidosis, a condition characterized by collections of granulomas that affect practically almost every organ in the body.
Sarcoidosis - Symptoms and Signs
Patients suffering from sarcoidosis typically complain about fatigue, lack of energy, weight loss, aches and pains. Cutaneous forms of the disease may be in many forms ranging from skin rash to scarring caused by severe fibrosis.
The heart is affected in approximately 20-30% of all patients but only 5% of these actually experience heart issues. In others heart involvement is asymptomatic.
If granulomas develop in the eye , the patient develops uveitis, uveoparotitis and inflammation of the retina. These conditions are associated with loss of visual acuity and rarely complete loss of vision.
Neurosarcoidosis is characterized by granulomas forming on the basal meninges. The granulomas affect cranial nerves as well and depending on the affected nerve patients develop characteristic neurological symptoms and signs.
And finally, if the scalp is affected, a person may experience patchy hair loss.
Treatment and Prognosis
Most patients suffering from sarcoidosis require no treatment. As a matter of fact treatment is considered not necessary in between 30 and 70% of all patients. Others, however, require medications that act against formation of new granulomas and are additionally prescribed drugs that deal with current symptoms (symptomatic treatment). Corticosteroids efficiently slow and sometimes even reverse the course of the disease. It is, however, possible that patients do not respond to corticosteroids. All in all, these medications are only indicated in case of severe and progressive sarcoidosis, affecting multiple organs, interfering with their function. Patients may be additionally prescribed azathioprine and methotrxate (both steroid-sparing agents) or cyclophosphamide, a chemotherapeutic agent.
It is possible for one to enter remission spontaneously. The disease may also progress and become chronic. Progression is rarely a cause of pulmonary fibrosis and associated lethal outcome. Prognosis is not so positive if granulomas affect the heart.
Unfortunately, people with sarcoidosis are prone to certain cancers such as lung cancer or lymphomas. Leukemia (hairy cell leukemia, acute myeloid leukemia and acute myeloblastic leukemia) may occur as well. This is the reason why apart from the primary disease, doctors should pay close attention and search for any sign of cancer in its early stage.
The onset of sarcoidosis is gradual and the condition sometimes withdraw spontaneously. For instance, two-thirds of all patients suffer no symptoms 9 years after the beginning of the disease, Furthermore, a half of all patients do experience relapse while only 10% of them end up with severe disability.
Sarcoidosis is confirmed to affect young individuals, both males and females. 16.5 out of 100.000 men and 19 out of 100,00 women develop sarcoidosis. The condition is reported to occur in all races. The incidence of sarcoidosis is the highest in Northern European countries (60/100.000) while people living in South America, Spain, India, Canada and the Philippines are not that affected. Namely, the incidence of sarcoidosis in the previously mentioned countries is much lower.
Such difference in incidence may be explained by the lack of screening programs in certain parts of the world. It is also possible to misdiagnose sarcoidosis and confuse it with tuberculosis, another granulomatous disease with similar symptoms.
Finally, there are some changes when it comes to races and sarcoidosis. The condition tends to be asymptomatic in Caucasians while people of African origin are more prone to develop severe form of sarcoidosis, the type that affects multiple organs.