A middle-aged woman with the initial symptom of acrocyanosis diagnosed with cold agglutinin disease: A case report.

Autoimmune hemolytic anemia is when autoantibodies attack red blood cells, leading to anemia. Cold agglutinin disease, a subtype of autoimmune hemolytic anemia, accounts for 13%-32% of cases. We present a middle-aged woman with a history of Raynaud's phenomenon who was admitted to the hospital due to acrocyanosis, weakness, and lethargy. Her blood tests revealed indirect hyperbilirubinemia, severe anemia, an increase in lactate dehydrogenase, a positive direct Coombs test, increased inflammatory factors, and a positive cold agglutinin antibody, confirming the diagnosis of cold agglutinin disease. Despite a 5-day hospital stay and initiation of treatments, she did not show a satisfactory response to the treatments. Cold agglutinin disease is a chronic disease that can initially present with mild symptoms. Early identification through appropriate laboratory tests is crucial. In severe cases, prompt initiation of proper treatment is necessary to prevent fatal outcomes.