ITP (immune thrombocytopenia)

Causes and who gets it

In ITP, for an unknown reason, the immune system makes antibodies that mark platelets. The marked platelets are destroyed, mainly in the spleen; platelet production may also fall. ITP is not contagious.

Conditions that can raise the risk include:

• Viral or bacterial infections; in children the disease sometimes starts after a viral infection
• Some antibiotics, antiviral medicines and anti-inflammatory medicines
• Very rarely, the measles-mumps-rubella (MMR) vaccine, especially in children
• Other immune diseases such as lupus, and some immune deficiencies
• In adults, pregnancy and some cancers

ITP is more common in children than in adults and affects girls and boys equally. In adults it is more common in women; chronic ITP is two to three times more common in women than in men. The American Society of Hematology estimates the frequency in the general population at 2 to 5 per 100,000 people.

Symptoms

ITP may cause no symptoms at all. When there are symptoms, most are related to bleeding:

• Easy or unexplained bruising
• Petechiae: pinpoint-sized red-purple spots on the skin, often on the front of the legs
• Purpura: larger red, purple or brownish-yellow patches caused by bleeding under the skin
• Nosebleeds, bleeding from the gums or inside the mouth
• Menstrual periods that are heavier or longer than usual
• Less often, blood in the urine or stool

If blood loss leads to anemia (a low red blood cell level), there may be tiredness, paleness and dizziness. In adults, marked tiredness is a common complaint that is easily overlooked. The lower the platelet count, the higher the risk of bleeding usually is. Bleeding in the stomach or intestines and bleeding in the brain are rare, but they can have serious consequences.

Diagnosis and tests

There is no single test that proves ITP on its own. Your doctor will ask about recent infections, vaccines, your medicines and any family history of bleeding, and will then examine you.

• Complete blood count (CBC): Measures platelets and the other blood cells. In ITP, usually only the platelets are low.
• Peripheral blood smear: An examination of the blood under a microscope. It can show findings that suggest another disease.
• Further tests if needed: Biochemistry tests, HIV and hepatitis screening, in some cases a Helicobacter pylori test, a pregnancy test and an abdominal ultrasound may be ordered.
• Bone marrow examination: Not needed at the first diagnosis in most patients; it may be ordered if there is no response to treatment or if another disease needs to be ruled out.

A normal platelet count is roughly 150,000–450,000/mm³; according to the Turkish Society of Hematology (Türk Hematoloji Derneği), in ITP it falls below 100,000/mm³. Sometimes the anticlotting substance in the tube (EDTA) makes platelets clump together, and the count looks lower than it really is. That is why ITP is not diagnosed from a single result.

Treatment approach

In ITP, the aim of treatment is not to get rid of the disease completely but to keep the platelet count at a safe level. Your doctor will look at your bleeding symptoms, platelet count, age, other illnesses and medicines together.

• Monitoring: For children with no bleeding, or with only bruising and petechiae on the skin, monitoring is recommended instead of medicine. Monitoring is also usually recommended for newly diagnosed adults who have no symptoms or only mild bleeding and a platelet count of 30,000/mm³ or above.
• Medicines: Considered for serious bleeding, a high risk of bleeding or a very low platelet count. Medicines that suppress the immune system, such as corticosteroids, are among the first options. If the response is not enough, medicines that increase platelet production or act on the immune system in other ways may be used.
• Removal of the spleen (splenectomy): May be considered for some patients whose ITP is long-lasting and does not respond to medicines; vaccines against infections are given beforehand.
• Platelet transfusion: In life-threatening bleeding, it raises the platelet count for a short time.

If ITP is linked to an infection, treating the infection may help the platelet count rise.

Everyday life and follow-up

Most people with ITP can carry on with their normal lives. To prevent bleeding, pay attention to the following:

• Painkillers: Some painkillers, such as aspirin and ibuprofen, interfere with how platelets work and can increase bleeding; they may be found in many over-the-counter medicines. Ask your doctor before starting a painkiller.
• Medicine list: Tell your doctor about all your medicines, supplements and herbal products.
• Sports: Contact sports such as boxing, soccer and karate, and activities with a risk of falling such as skiing and horse riding, can lead to bleeding. You may be asked to avoid these while your platelet count is very low.
• Dental care: Use a soft toothbrush and go for regular dental checkups. Ask your doctor before a tooth extraction, a filling or tartar cleaning.
• Procedures: Before any surgery or procedure, say that you have ITP.
• Information card: Carry a card with your diagnosis and your doctor’s contact details; if your child has ITP, the family should carry the card.
• Infections: Viral infections can lower platelets. Get your vaccines after checking with your doctor.

If your spleen has been removed, tell your doctor right away if you have a fever. Do not skip your follow-up blood counts.

Pregnancy, children and special situations

Children: In many children, ITP gets better on its own within a few weeks or months and usually does not come back. ITP that lasts longer than a year is called chronic ITP; recovery can still happen years later. Protect your child from activities with a high risk of falls and head injury; use a helmet, knee pads and elbow pads if needed. Ask your child’s doctor about any limits for school and sports.

Pregnancy: During pregnancy, platelets can fall slightly even in healthy women. This is called gestational thrombocytopenia; it is common and usually causes no problems. Serious conditions such as preeclampsia, however, can lower platelets a lot. Pregnant women with ITP have regular blood counts, and treatment is given before delivery if needed. The way the baby is delivered is decided on obstetric grounds. The mother’s antibodies can pass to the baby; a low platelet count in the baby usually gets better within a few days. That is why the baby’s platelet count is checked at birth. Before delivery, remind the team that you have ITP.

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