Livedo Racemosa, Reticulated Ulcerations, Panniculitis and Violaceous Plaques in a 46-year-old Woman

Clinically amyopathic dermatomyositis (CADM) is a subset of dermatomyositis (DM) that has conventional cutaneous manifestations of DM, but paradoxically, little or no muscle involvement. In 2005, a novel antibody was described in association with CADM - anti-melanoma differentiation-associated gene 5 (anti-MDA5). Patients with this serologic marker have a characteristic mucocutaneous phenotype consisting of skin ulceration among other signs. We describe the case of a 46-year-old woman with CADM, elevated anti-MDA5 autoantibodies, and unusual clinical features (livedo racemosa, florid acral edema) among the classical phenotype of MDA5 DM (arthralgias, ulcerations, panniculitis) and classical DM lesions (Gottron papules, heliotrope rash). The patients did not develop interstitial lung disease or internal malignancies and experienced a rapid response to prednisolone and intravenous immunoglobulins. After 2 years, she has no relapse of her cutaneous disease and continues 5 mg prednisolone and 2 g/kg kilogram of intravenous immunoglobulin every 3 months for maintenance. Our case highlights the clinical heterogeneity of CADM and underscores the importance of a comprehensive approach to DM patients. It was previously postulated that anti-MDA5 antibody could target vascular cells and compromise vascular function, the presence of livedo racemosa lesions, and MDA5 antibodies in a patient with negative thrombophilia workup, reinforce this idea. This is the first case, to our knowledge, of CADM with acral panniculitis and livedo racemosa.