SARCOIDOSIS HAS MANY CLINICAL MANIFESTATIONS.

Sarcoidosis is an acquired idiopathic, multisystem disorder characterized by noncaseating granulomas in the involved tissue. This condition of unknown

origin is most common in African Americans and northern Europeans. The organs most commonly affected are the lungs, lymph nodes, skin, and eyes. [1-4] Sarcoidosis typically causes no significant derangements, but on occasion the granulomas can become so large or numerous that they impair the function of the affected organ.

Sarcoidosis is the result of an immune dysfunction. The immunological features associated with the condition include impaired delayed-type hypersensitivity reactions to cutaneous antigens (anergy), a shift of helper T lymphocytes from the peripheral blood to sites of disease activity (lymphopenia), and increased production of circulating antibodies. [5] At the site of a non-specific insult, an exaggerated helper T lymphocyte response causes those cells to accumulate, along with macrophages and other elements, until a granuloma forms.

In patients with systemic sarcoidosis, skin lesions occur in 20% to 35% of cases. [6] Cutaneous sarcoidosis without systemic involvement occurs in approximately 25% of patients. [7] Because of its diverse skin manifestations, sarcoidosis is most frequently diagnosed by a dermatologist. Table 1 lists the various clinical manifestations of sarcoidosis of the skin. The skin lesions may be specific or nonspecific. Specific skin lesions are generally associated with chronic disease and demonstrate noncaseating granulomas in the dermis on histological examination. Nonspecific skin lesions are seen primarily with acute disease and noncaseating granulomas are absent.

Specific Skin Lesions

Minus and Grimes reported that flesh-colored waxy papules are the most frequent cutaneous manifestation of sarcoid in African Americans. [8] These skin lesions occur mainly on the face and are frequently symmetrical. Common locations include the periorbital, perinasal, intranasal, perioral, and occipital areas (Figures 1 and 2). Lichenoid papules of sarcoidosis are multiple and violaceous (purplish) skin lesions that are usually found clustered on the trunk. [9]

Hypopigmented macules either alone or in combination with other sarcoid skin lesions occur quite often in African American patients [10,11] (Figure 3). These light areas of skin can resemble other dermatological conditions, such as tinea versicolor, post-in-flammatory hypopigmentation, vitiligo, and T cell lymphoma of the skin (mycosis fungoides). The diagnosis is easily made by performing a skin biopsy, which in sarcoidosis will reveal noncaseating granulomas.