Cold autoimmune hemolytic anemia caused by cold-reacting antibodies. Autoantibodies that bind to the erythrocyte membrane leading to premature erythrocyte destruction (hemolysis) characterize autoimmune hemolytic anemia. Presentation
A common complaint among patients with cold agglutinin disease is painful fingers and toes with purplish discoloration associated with cold exposure. In chronic cold agglutinin disease, the patient is more symptomatic during the colder months. Cold agglutinin mediated acrocyanosis differs from Raynaud phenomenon. In Raynaud phenomena, caused by vasospasm, a triphasic color change occurs, from white to blue to red, based on vasculature response. No evidence of such a response exists in cold agglutinin disease. Other symptoms

Respiratory symptoms: May be present in patients with M pneumoniae infection. Hemoglobinuria (the passage of dark urine that contains hemoglobin), A rare symptom that results from hemolysis, this may be reported following prolonged exposure to cold, hemoglobinuria is more commonly seen in paroxysmal cold hemoglobinuria. Chronic fatigue, Due to anemia. Causes
Cold agglutinins develop in more than 60% of patients with infectious mononucleosis, but hemolytic anemia is rare. Classic chronic cold agglutinin disease is idiopathic, associated with symptoms and signs in relation to cold exposure. Causes of the monoclonal secondary disease include the following:

B-cell neoplasms - Waldenström macroglobulinemia, lymphoma, chronic lymphoid leukemia, myeloma
Non hematologic neoplasmsCauses of polyclonal secondary cold agglutinin disease include the following:

Mycoplasma infections. Viral infections: Infectious mononucleosis due to Epstein-Barr virus (EBV) or CMV, Mumps, varicella, rubella, adenovirus, HIV, influenza, hepatitis C.
Bacterial infections: Legionnaire disease, syphilis, listeriosis and Escherichia coli. Parasitic infections: Malaria and trypanosomiasis.
Cutibacterium acnes  almost exclusively causes endocarditis on prosthetic heart valves. Signs and symptoms
Fever occurs in 97% of people; malaise and endurance fatigue in 90% of people. A new or changing heart murmur, weight loss, and coughing occurs in 35% of people. Vascular phenomena: septic embolism (a piece of infected debris or tissue breaking off and traveling through the bloodstream to a distant site) (causing thromboembolic problems such as a stroke or gangrene of the fingers), Janeway lesions (painless hemorrhagic cutaneous lesions on the palms and soles), bleeding in the brain, conjunctival hemorrhage, splinter hemorrhages, kidney infarcts, and splenic infarcts. Infective endocarditis can also lead to the formation of mycotic aneurysms. Immunologic phenomena: glomerulonephritis which allows for blood and albumin to enter the urine, Oslers nodes ("ephemeral spots of a painful nodular erythema, chiefly in the skin of the hands and feet"), Roths spots on the retina, positive serum rheumatoid factor
Other signs may include night sweats, rigors, anemia, spleen enlargement

Cause
Many microorganisms can cause infective endocarditis. These are generally isolated by blood culture, where the patients blood is drawn and any growth is noted and identified. The term bacterial endocarditis (BE) commonly is used, reflecting the fact that most cases of IE are due to bacteria; however, infective endocarditis (IE) has become the preferred term. Bacterial
Staphylococcus aureus is the leading cause of infective endocarditis in most parts of the world and is responsible for about 31% of cases. Staphylococcus aureus is the most common cause of endocarditis in people who use intravenous drugs.