Review Question - QID 109703

This patient who experiences acrocyanosis in peripheral body parts during the winter after a mononucleosis (Epstein-Barr virus) infection most likely has cold agglutinin disease. This disease is also associated with mycoplasma, which has no cell wall.

Cold agglutinin disease is a form of autoimmune hemolytic anemia that is caused by production of self-reactive IgM antibodies. These antibodies are most active at colder temperatures and function to fix complement to red blood cells. Subsequent lysis of these red blood cells causes extravascular hemolysis and painful discoloration of colder parts of the body such as the fingers and toes. It is important to remember that the antibodies responsible for cold agglutinin disease are often triggered by either mononucleosis or mycoplasma pneumoniae.

Incorrect Answers:
Answer 1: Acid-fast bacteria include mycobacteria, which can cause pulmonary symptoms and lytic bone lesions; however, they are not associated with cold agglutinin disease.

Answer 2: Gram-negative bacteria include zoonotic bacteria such as Yersinia species that may lead to peripheral pain and discoloration; however, they are not associated with cold agglutinin disease.

Answer 3: Gram-positive bacteria include Streptococcus and Staphylococcus species that can cause rashes such as scarlet fever or toxic shock syndrome; however, they are not associated with cold agglutinin disease.

Answer 5: Spirochetes such as Treponema species can cause peripheral neuropathy and damage such as in the chronic form of syphilis; however, they are not associated with cold agglutinin disease.

Bullet Summary:
Cold agglutinin disease can cause pain, numbness, and discoloration in more peripheral parts of the body and is associated with mononucleosis and mycoplasma.