Annular Atrophic Plaques on the Forearm

Sarcoidosis is a systemic noncaseating granuloma­tous disease of unknown etiology. The skin is the second most common location for disease mani­festation following the lungs.¹ Cutaneous sarcoidosis is present in 35% of patients with sarcoidosis and may be further subtyped by its morphologic characteristics (eg, hyperpigmented, papular, nodular, atrophic, ulcer­ative, psoriasiform). Cutaneous sarcoidosis has an increased tendency to occur at areas of prior injury such as surgeries or tattoos.² Although sarcoidosis affects all races and sexes, it is more prevalent in women and in the black population.³

The clinical presentation of sarcoidosis is difficult due to its morphologic variation, allowing for a wide differential diagnosis. With our patient’s presentation of atrophic plaques, the differential diagnosis included granuloma annulare, necrobiosis lipoidica, tumid lupus erythematosus, leprosy, and sarcoidosis; however, biopsy is required for definitive diagnosis. The characteristic histopathology for cutaneous sarcoidosis includes nonca­seating granulomas (Figure, A) composed of epithelioid histiocytes with giant cells surrounded by a lympho­cytic infiltrate. Noncaseating granulomas are consid­ered specific to sarcoidosis and are present in 71% to 89% of biopsied lesions.⁴ Interestingly, our patient pre­sented with a rare subtype of atrophic ulcerative cutane­ous sarcoidosis, necrobiosis lipoidica–like sarcoidosis, which is more common in females and in the black population. It is characterized by pink to violaceous plaques with depressed centers and prominent necrotiz­ing granuloma (Figure, B) on histopathology. In a small case series, all 3 patients with necrobiosis lipoidica–like sarcoidosis were female and had systemic involvement at the time of diagnosis.⁵

A, Microscopic examination of the biopsied lesion revealed a classic noncaseating granuloma with multinucleated giant cells (H&E, original magnification ×100). B, A palisading necrotizing granuloma consistent with necrobiosis lipoidica–like cutaneous sarcoidosis also was seen (H&E, original magnification ×100).

Sarcoidosis typically is a systemic disease with only a limited number of cases presenting with isolated cutane­ous findings. Therefore, patients require a systemic evalu­ation, which may include a chest radiograph, complete blood cell count, ophthalmologic examinations, thyroid testing, and vitamin D monitoring, as well as an echocar­diogram and electrocardiogram.²

Treatment is guided by the severity of disease. For isolated cutaneous lesions, topical or intralesional high-potency steroids have been shown to be effective.^6,7 Several studies also have shown phototherapy and laser therapy as well as surgical excision to be beneficial.^8-10 Once cutaneous lesions become disfiguring or systemic involvement is found, systemic corticosteroids or other immunomodulatory medications may be warranted.¹¹ Our patient was started on intralesional and topical high-potency steroids, which failed, and she was transitioned to methotrexate and adalimumab. Unfortunately, even with advanced therapies, our patient did not have notableresolution of the lesions.