Complex Regional Pain Syndrome: What the Dermatologist Should Know.

Reflex sympathetic dystrophy is a subtype of complex regional pain syndrome, a condition characterized by persistent post-injury extremity pain. Temperature and sweating changes, edema, mobility changes, and a variety of hair, nail, and skin sequelae have been described. Only 23 articles published since 1990 describe dermatologic changes in CRPS. Given this paucity of literature, we present a case to further elucidate cutaneous manifestations of CRPS. Our patient is a 52-year-old Caucasian woman with a 19-year history of reflex sympathetic dystrophy who has presented with several dermatologic complaints. She was first referred to the clinic due to episodic, mildly tender, clustered, non-blanching, and non-palpable petechiae on the legs bilaterally, which was histologically consistent with leukocytoclastic vasculitis. No systemic involvement was identified and symptoms resolved with topical steroids. The patient was also noted to have severe ten toenail dystrophy without any evidence of onychomycosis based on multiple cultures and PAS staining of clipped nails. Avulsion of the great toenail was performed to provide symptomatic relief. Incidentally, the patient was found to have lower extremity and facial hypotrichosis on physical exam. Further, she required increased lidocaine administration in addition to pre and post-procedure lidocaine and prilocaine 5% emulsion cream for various office procedures, suggestive of lidocaine insensitivity. This case captures previously described cutaneous manifestations of CRPS such as vasculitis, nail dystrophy, extremity hypotrichosis, and telangiectasia, along with newly described potential manifestations about which dermatologists should be aware, including facial hypotrichosis and lidocaine insensitivity. J Drugs Dermatol. 2018;17(5):532-536.