Thrombocytopenia Differential Diagnosis
Thrombocytopenia refers to a condition characterized by an abnormally low level of platelets in the blood. This can lead to an increased risk of bleeding and bruising. The differential diagnosis for thrombocytopenia is broad and can be categorized based on the likelihood and potential impact of missing a diagnosis.
Single Most Likely Diagnosis
- Immune thrombocytopenic purpura (ITP): This is an autoimmune disease where the body's immune system mistakenly attacks and destroys its own platelets, leading to a low platelet count. It is one of the most common causes of thrombocytopenia and can present with petechiae, easy bruising, and sometimes more severe bleeding.
Other Likely Diagnoses
- Drug-induced thrombocytopenia: Certain medications can induce the formation of antibodies against platelets, leading to their destruction. Common culprits include heparin, quinine, and sulfonamides.
- Bone marrow failure: Conditions such as aplastic anemia, leukemia, or lymphoma can lead to a decrease in platelet production.
- Disseminated intravascular coagulation (DIC): A condition characterized by both widespread clotting and bleeding in the vascular system, which can consume platelets and lead to thrombocytopenia.
- Liver disease: Cirrhosis and other liver conditions can lead to splenic sequestration of platelets, resulting in thrombocytopenia.
- Vitamin B12 or folate deficiency: These deficiencies can impair the production of platelets in the bone marrow.
Do Not Miss Diagnoses
- Thrombotic thrombocytopenic purpura (TTP): A rare disorder of the blood-coagulation system, causing extensive microscopic clots to form in the smallest blood vessels throughout the body. These clots consume platelets, leading to thrombocytopenia, and can cause organ dysfunction.
- Hemolytic uremic syndrome (HUS): Similar to TTP, HUS is characterized by the formation of blood clots in small blood vessels, which can lead to thrombocytopenia, kidney failure, and hemolytic anemia.
- Sepsis: Severe infections can lead to thrombocytopenia through various mechanisms, including DIC, and are critical to identify due to their high mortality rate if not promptly treated.
- HIV infection: HIV can cause thrombocytopenia through immune-mediated mechanisms, direct infection of megakaryocytes, or as a result of opportunistic infections or medications.
Rare Diagnoses
- Congenital thrombocytopenias: These are a group of rare disorders characterized by low platelet counts present at birth, often associated with other physical anomalies or syndromes.
- Heparin-induced thrombocytopenia (HIT): An immune-mediated reaction to heparin that can lead to the formation of antibodies that activate platelets, causing thrombosis and thrombocytopenia.
- Post-transfusion purpura (PTP): A rare immune-mediated condition that occurs after blood transfusion, leading to the destruction of platelets.
- May-Hegglin anomaly: A rare genetic disorder affecting platelets and white blood cells, leading to thrombocytopenia and characteristic inclusions in neutrophils.