Sarcoidosis Has Many Clinical Manifestations

Minority Health Today, July, 2000 by Valerie D. Callender

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.

Sarcoidal plaques present as raised erythematous /violaceous, indurated, and shiny skin lesions on the face and extremities (Figure 4). They may become annular in shape and the center of the plaque may become atrophic. If a skin lesion has telangiectatic blood vessels on the surface, it is described as angiolupoid. [12]

The most characteristic of all sarcoid skin lesions is lupus pernio. [13] It presents as chronic sarcoidal plaques with a predilection for the nose, ears, lips, and malar areas of the face. Permanent scarring can occur. Lupus pernio is associated with extensive pulmonary infiltration and scarring, chronic uveitis, and bone cysts. When present on the nose, granulomatous infiltration of the nasal mucosa and the upper respiratory tract can occur. [14] This may progress to destruction of the nasal septum. If a patient presents with lupus pernio, the clinician needs to examine the hands. A bulbous or sausage-shaped appearance of the fingers indicates the presence of an underlying bone lesion. Radiological examination will likely reveal bone cysts.

Subcutaneous nodules of sarcoidosis, also called Darier-Roussy sarcoidosis, [15] appear most often on the arms and legs. These are typically nontender. The overlying skin can be flesh-colored or hypopigmented. These subcutaneous nodules may occur alone [16] or in association with other cutaneous lesions. [17] On biopsy, these show noncaseating granulomas in the dermis and subcutaneous tissue.

Ichthyosiform sarcoidosis is an uncommon skin manifestation of sarcoidosis. [17-20] It presents as hyperpigmented polygonal-shaped scaly areas on the lower extremities (Figure 5). They appear "fish-like" and on histo-logical examination, noncaseating granulomas are found. This type of sarcoidosis can appear either concurrently with or precede the diagnosis of systemic sarcoidosis. The differential diagnosis of a patient who presents with acquired ichthyosis of the skin should also include human immunodeficiency virus disease, lymphoproliferative skin malignancies (such as non-Hodgkin's lymphoma), and cancer of the breast, cervix, or lungs. [21]

Scars from herpes zoster, [22] trauma, surgery, tattoos, [23] or venipuncture also may become swollen and tender and show noncaseating granulomas consistent with sarcoidosis. This can represent either an initial presentation or a reactivation of pre-existing disease.