thrombocytopénia

Thrombocytopenia is a medical condition characterized by a lower-than-normal number of platelets in the blood. Platelets, also known as thrombocytes, are small, irregular-shaped cell fragments that play a crucial role in blood clotting. When their count falls below a certain threshold, the body's ability to form clots is impaired, leading to an increased risk of bleeding.

The causes of thrombocytopenia are diverse and can include decreased platelet production by the bone marrow, increased destruction of platelets, or their sequestration in the spleen. Conditions affecting bone marrow production include aplastic anemia, certain leukemias, and viral infections like hepatitis C. Immune-mediated destruction is a common cause, where the body's immune system mistakenly attacks and destroys its own platelets, as seen in immune thrombocytopenia (ITP). Medications, certain cancers, and severe infections can also lead to increased platelet destruction or consumption. Enlargement of the spleen (splenomegaly) can cause platelets to be trapped, reducing their circulating count.

Symptoms of thrombocytopenia can range from mild to severe, depending on the platelet count. Mild cases may be asymptomatic and discovered incidentally during routine blood tests. As the platelet count drops, individuals may experience easy bruising, prolonged bleeding from cuts, nosebleeds, bleeding gums, and petechiae, which are small, pinpoint red or purple spots under the skin caused by bleeding. In severe cases, internal bleeding can occur, which may manifest as blood in the urine or stool, or heavy menstrual bleeding.

Diagnosis typically involves a complete blood count (CBC) to confirm the low platelet count. Further investigations may be performed to identify the underlying cause, including bone marrow biopsy, tests for infections or autoimmune disorders, and assessment of spleen size. Treatment strategies are tailored to the specific cause and severity of the thrombocytopenia and may involve addressing the underlying condition, discontinuing offending medications, or using therapies to increase platelet production or reduce their destruction, such as corticosteroids or intravenous immunoglobulin.