Sarcoidosis skin lesions

In the United States, chronic skin sarcoidosis is more common in African Americans than Caucasians. In ACCESS, where patients were evaluated within six months of diagnosis, 19.7 % (64/325) of African Americans had specific (granulomatous) sarcoidosis skin lesions compared to 13.0% (51/393) of Caucasians (chi-square = 5.5, p < 0.05) (25). 

Another distinctive specific sarcoidosis skin lesion is lupus pernio, relatively symmetric, violaceous, indurated plaque-like and nodular sarcoidal lesions occurring on the nose, ear lobes, cheeks, and digits (Figs. 6 and 7). Lupus pernio... 

Figure 8 (See color insert.) Sarcoidosis skin lesions in a tattoo.

Erythema nodosum is the main nonspecific cutaneous manifestation of sarcoidosis. They present as violaceous to erythematous tender nodules on the extremities. In general, nonspecific sarcoidosis skin lesions are associated with an acute form of sarcoidosis that has a good prognosis where eventual resolution of the disease is common (39). 

The diagnosis of specific sarcoidosis skin lesions usually requires a confirmatory biopsy. On occasion, a clinical diagnosis of skin sarcoidosis may be made if the lesions are typical (e.g., lupus pernio or lesions present on scar tissue). Sarcoidosis is not the only cause of granulomatous inflammation of the skin, and other potential causes must be carefully excluded. Usually the diagnosis of skin sarcoidosis is not secure without evidence of extracutaneous granulomatous disease. 

Recognized in 1961 (KIO), these are now well described (B18) and mimic the syndrome of mixed cryoglobulinemia (see 6.13). Skin lesions in this condition are raised, painful, and edematous with or without necrosis. Biopsy always reveals arteritis with a mononuclear and neutro-phile infiltrate. There is in most cases a preceding history of rheumatoid arthritis, Sjogren s syndrome, syphilis, sarcoidosis or other hyperimmune states, and this will dominate the clinical findings. Rarely the protein interactions build up to a level presenting as a viscosity syndrome so that this group can overlap with 7.7.1 unless the serum is carefully examined. 

The frequency of chronic skin lesions in sarcoidosis ranges from 9% to 37% in various series (25-27). In A Case Control Etiology of Sarcoidosis study (ACCESS) sponsored by the National Institute of Health, chronic skin involvement was second in frequency [113/718 (15.7%)] only to lung involvement (28). Although cutaneous involvement may occur at any stage of the disease, it is most often present at the onset (25). 

Erythema nodosum, a nongranulomatous inflammatory skin lesion that occurs in approximately 10% of sarcoidosis patients (Fig. 5) (28). It is more common in women than men (28) and is also common in Europeans, Puerto Ricans, and Mexicans, particularly in women of childbearing age of these ethnicities (29). 

The diagnosis of skin sarcoidosis tends to be made rapidly relative to other organ involvement with sarcoidosis because the skin lesions are evident and can be easily biopsied. In a cohort of ACCESS patients, the patients with skin sarcoidosis were diagnosed significantly faster than those with pulmonary sarcoidosis (30). Patents with nonspecific skin lesions such as erythema nodosum do not demonstrate granulomatous inflammation on biopsy. Therefore, skin biopsies should be avoided in these patients as the procedure has no value in their diagnosis. 

Cutaneous sarcoidosis lesions are divided into two categories specific and nonspecific. Specific lesions reveal granulomatous inflammation on biopsy. Nonspecific skin findings are reactive inflammatory lesions that do not exhibit sarcoidal granulomas. 

Despite the diversity in appearance, there are several clinical presentations that are typical for cutaneous sarcoidosis. The most common presentation is the papular form. These lesions are firm, 2 to 5 mm papules, and often have a translucent red-brown or yellow-brown qipearance (31). The yellow-brown color has been likened to apple jelly (31). Papular lesions occur most commonly on the face and neck with a predilection for periorbital skin. 

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