Unilateral lower extremity edema caused by infiltrative sarcoidosis

Cutaneous sarcoidosis: differential diagnosis

Sarcoidosis is a multisystem disease with cutaneous lesions present in 20%-35% of patients. Given the wide variability of clinical manifestations, it is one of the "great imitators," making it necessary to consider clinical, epidemiological, radiographic, laboratory, and histopathological criteria to make the diagnosis. Cutaneous lesions have been classified as specific and nonspecific, depending on the presence of noncaseating granulomas on histologic studies. Specific lesions include maculopapules, plaques, nodules, lupus pernio, scar infiltration, alopecia, ulcerative lesions, and hypopigmentation among others. Nail, mucosal, and childhood sarcoidosis represent a distinct subset of the disease process. The most common nonspecific lesion is erythema nodosum. Others include calcifications, prurigo, erythema multiforme, nail clubbing, and Sweet syndrome. The importance of considering cutaneous sarcoidosis in the clinical differential diagnosis of a given skin lesion relies on the association with systemic involvement and the convenience of the skin as a tissue source for histologic analysis.

Sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown cause that most commonly affects the lungs, lymph nodes, skin, eyes, spleen, bone, and glandular tissue. The diagnosis is made when characteristic histologic findings are demonstrated and other granulomatous processes are excluded. It can be an acute or chronic debilitating disease, but in patients with acute disease the process can be self-limited. Multiple therapeutic options have been described both for the cutaneous and systemic lesions of sarcoidosis. Steroids, however, remain the cornerstone of therapy.

Sarcoidosis

Sarcoidosis is a systemic noncaseating granulomatous disorder of unknown origin. The cutaneous manifestations of sarcoidosis often enable the dermatologist to be the first physician to make the diagnosis. This article reviews essential sarcoidosis pathophysiology, clinical polymorphisms, systemic evaluation, and treatment modalities for cutaneous sarcoidosis to further enhance the dermatologist's understanding of this disease entity.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be familiar with the theories of the pathogenesis of sarcoidosis, its cutaneous manifestations, its various syndromes and associations, and its presentation in children. Participants should also be more knowledgeable about diagnostic evaluation, measurement of disease progression, treatment modalities, and the prognosis and mortality data of sarcoidosis.

Cutaneous sarcoidosis in black South Africans

BACKGROUND

It has been observed that, in the USA, sarcoidosis is more common in African-Americans than in other races. It has also been noted that sarcoidosis in African-Americans is characterized by more severe extrapulmonary involvement and more exuberant skin lesions. There is little information on sarcoidosis in black Africans.

METHODS

Fifty-four black South African patients with cutaneous lesions of sarcoidosis proven by biopsy were prospectively studied. Dermatologic and ophthalmologic examinations and chest X-rays were performed in all patients. Other investigations relevant in the diagnosis of extracutaneous sarcoidosis were also performed in a variable number of patients.

RESULTS

In 40 patients (71%), systemic sarcoidosis was found with lung, eye, and acral bone involvement being most common. Great variations in the morphology of skin lesions were observed. In one-quarter of patients, atypical cutaneous lesions (hypopigmented, ichthyosiform, lymphedematous, mutilating, ulcerative, verrucous) were found. Lupus pernio, once thought to be confined to Northern Europe, was observed in five patients in the subtropical milieu of South African Transvaal. Sarcoidal dactylitis with nail changes was seen in eight patients. Fibrinoid necrosis was found in 12% of the biopsies.

CONCLUSIONS

Sarcoidosis in black South Africans is characterized by extensive cutaneous involvement. The lesions are morphologically extremely variable, frequently atypical, and often demonstrate fibrinoid necrosis on histology.