Sarcoidosis is a granulomatous disease that can affect any organ system.
In the United States, sarcoidosis has a higher prevalence in African Americans and Caucasians of Scandinavian descent.
Sarcoidal lesions manifest with multiple morphologic features and can be mimickers of other inflammatory skin disease. Early detection of skin disease requires a systemic workup for pulmonary and other organ involvement.
There is a connection between genetic and environmental exposure factors in patients with sarcoidosis.
Sarcoidosis is a multisystem, granulomatous disease that can affect any organ system. The skin is the most common extrathoracic location.1,2 Even though the first documented case of cutaneous sarcoidosis dates back to 1869, its etiology remains an enigma.2,3,4,5 Evidence suggests that sarcoidosis develops when a genetically susceptible individual comes in contact with an unknown antigen (eg, bacterial, viral, or environmental) and their body elicits an immunologic cascade that produces noncaseating granulomas most commonly found in the lung, skin, heart, and liver [Figure 74-1]. Cutaneous sarcoid lesions have the unique capability of mimicking both rare and common skin disorders, often making diagnosis a challenge. Sarcoidosis is found more commonly in skin of color groups. Not only is sarcoidosis more common in patients with skin of color, but these patients also present with more advanced disease and have a poorer prognosis. There are numerous well-known historical and modern figures who had or have sarcoidosis. Such celebrities include Floyd Mayweather, Sr. (former boxer/trainer), Mahalia Jackson (gospel singer), Bernie Mac (comedian), Reggie White (American football player), Daisy Fuentes (actress/model), Manning Marable (author), Ludwig van Beethoven (musician), and Tisha Campbell Martin (actress/model), to name a few.
Illustration of the molecular cascade suspected in sarcoidosis. Molecular mimicry seems to be the most important factor for the heterogeneous clinical presentation and the immunopathogenesis of sarcoidosis. APC, antigen-presenting cell; GM-CSF, granulocyte-macrophage colony-stimulating factor; HLA, human leukocyte antigen; MCP-1, monocyte chemoattractant protein-1; MIP, macrophage inflammatory protein; Th, T helper; TNF-α, tumor necrosis factor-α.
Sarcoidosis affects all races and ethnicities.4,5 In the United Sates, there is a higher prevalence in African Americans (35.5 to 64 cases/100,000) and other groups with skin of color compared to Caucasians (10.9 to 14 cases/100,000).6 Scandinavia has the world’s highest prevalence of reported cases (50 to 60 cases/100,000).2,3,4,7
A worldwide review of sarcoidosis that included 3676 patients of Japanese, Caucasian, darker skin of color American, Puerto Rican, and Mexican descent reported no gender predilection, and most patients were diagnosed before the age of 40.8 A study in Singapore highlighted 25 patients and found that although Indian patients represented only 7.7% of the general population, they made up 52% of sarcoidosis patients in the study.9