A 75-year-old woman with primary antiphospholipid syndrome presenting with livedoid vasculopathy

The clinical presentation of primary antiphospholipid syndrome (PAPS) can vary, often mimicking many other medical conditions. Therefore, it is difficult to diagnose at the first presentation because of the absence of classical symptoms. We described an unusual presentation of PAPS mimicking livedoid vasculopathy (LV), where the only diagnostic clue at the initial presentation was skin lesions in both lower legs. A 75-year-old Han Chinese woman presented with features mimicking LV, without clinically significant antiphospholipid syndrome (APS). After many relevant laboratory examinations and histopathological examination, the patient was finally diagnosed as having PAPS. LV should not be treated as an independent disease, but as a skin manifestation. A high degree of suspicion of APS is needed in patients presenting or diagnosed with LV. Early interventions are necessary to prevent and reduce the risk of thrombosis. This case presents a rare clinical manifestation and provides significant information on PAPS.