Atypical Cutaneous Presentations of Sarcoidosis: Two Case Reports and Review of the Literature.

PURPOSE OF REVIEW: The goal of this review is to provide the reader with an updated summary of the cutaneous manifestations of systemic sarcoidosis, with a particular emphasis on the predilection of sarcoidosis for scars, tattoos, and other areas of traumatized skin.

RECENT FINDINGS: While the mechanism underlying the propensity for traumatized skin to develop sarcoidosis lesions remains unclear, several theories have been proposed including the idea that cutaneous sarcoidosis represents an exuberant, antigen-driven foreign-body response, as well as the theory that traumatized skin represents an immunocompromised district with altered local immune trafficking and neural signaling. In this review, we present two cases in which the development of cutaneous lesions in scars and tattoos was integral to the diagnosis of systemic sarcoidosis. We then review the various cutaneous manifestations of systemic sarcoidosis, the clinical characteristics and differential diagnosis of scar and tattoo sarcoidosis, the proposed mechanism by which traumatized skin is prone to developing sarcoidosis lesions, and current treatments for cutaneous sarcoidosis.