Thrombocytopenia (low blood platelet count): ICD-10: D69.6

Petechiae (small, dot-shaped bleeding) in the skin of the calf and foot by the low number of platelets (thrombocytopenia). Manasal R, Indian J Pharmacol (2013). CC BY NC SA 3.0

Definition

Normally, the number of platelets (platelets) is measured in blood samples between 150.000-450.000 x 10⁹/ L. thrombocytopenia:

• Platelet count below 100.000 x 10⁹/L
• Severe thrombocytopenia: 1-20.000 x 10⁹/L
• Moderate: 10 - 30.000 x 10⁹/L
• Mild: 30 - 50.000 x 10⁹/L

Causes

Cause of thrombocytopenia is divided into either reduced production or increased platelet destruction

• Reduced production of platelets (in the bone marrow)

  • Leukemia and other Diseases of the bone marrow
  • Some types of anemia (Low hemoglobin)
  • Viral infections (including Hepatitis C or HIV)
  • Chemotherapy and other drugs (see below)
  • Large alcohol consumption
  • hypothyroidism (low metabolism)

Increased destruction of platelets

• Autoimmune diseases (SLE, Antifosfolipid syndrome, Rheumatoid arthritis (possibly with Felty's syndrome), Still illness in adulthood
• Sepsis (bacteria)
• Thrombotic Thrombocytopenic purpura
• Immune thrombocytopenia (ITP)
• Pregnancy

• Medication

  • Cytotoxic drugs
  • Heparin
  • Sulpha-preparations
  • Epilepsy drugs
  • Hydroxychloroquine /Plaquenil (Very rare)

Symptoms

• Increased bleeding tendency (most often when the number of platelets is lower than 50.000)
• Superficial small red bleeding, most often on the lower legs
• Prolonged bleeding after small injuries
• Bleeding from the mucous membranes and gums
• Unusually strong menstrual bleeding
• Potentially life-threatening bleeding if the number of platelets is below 10.000 / micro liters

Diagnosis

Clinical examination

• Look for bleeding under the skin, the mucous membranes and in joints. Examine the abdomen and the spleen size

Blood tests

• Complete cell count with red and white blood cells with differential counts and platelets in citrate blood (prevents aggregates and error measurement)
• Blood smears (schistocytes and abnormal platelets)
• ANA (Autoimmune disease)
• Haptoglobin (hemolysis)
• TSH (hypothyroidism)
• HIV, Hepatitis C, antiphospholipid antibodies

Bone marrow examination

Treatment

• Treatment of thrombocytopenia is dependent on the cause and must be assessed in each case

Literature

• Rondina MT, 1995 (Focus on Heparin-induced)