Livedo reticularis: An underutilized diagnostic clue in cholesterol embolization syndrome

Background: Cholesterol embolization syndrome (CES) is an increasingly reco gnized cause of acute renal insufficiency, which must be differentiated fro m other forms of systemic vasculitis by histologic examination of biopsies from involved organs. This report describes the optimal methods for detecti on and biopsy of areas of skin involved with livedo reticularis to confirm the diagnosis of CES. Methods: This report describes 8 patients with unexpl ained acute renal insufficiency in whom the diagnosis of CES was suspected based on their clinical history. Results: A detailed skin examination perfo rmed in both supine and upright postures demonstrated the presence of previ ously unrecognized livedo reticularis, which was more evident during uprigh t posture in all subjects. In 2 subjects, questionable areas of livedo reti cularis noted in supine posture became readily demonstrable during upright posture. Livedo reticularis was apparent only during upright posture in 2 s ubjects. Biopsies of areas of skin involved with livedo reticularis demonst rated cholesterol emboli in 6 of 8 patients and were normal in the remainin g 2 patients. One patient progressed to end-stage renal disease and one was lost to follow-up. In the remaining 6 patients, renal insufficiency initia lly progressed but did not require dialytic therapy. Renal function returne d to baseline levels and livedo reticularis resolved without recurrence in these patients. No subjects developed clinical or laboratory evidence of sy stemic vasculitis. Conclusions: Livedo reticularis is a common but often un recognized finding in CES that may not be evident during routine examinatio n performed in the supine posture. Deep cutaneous biopsy of areas of livedo reticularis can be safely used to confirm the presence of cholesterol embo li, thus avoiding the increased morbidity of biopsy of either pregangrenous skin lesions or visceral organs. Many patients with CES regain renal funct ion during long-term follow-up.