Immune Thrombocytopenia
Diagnosis

ITP is suspected when an otherwise healthy patient has symptoms of a low platelet count, or is found to have a low platelet count on a routine complete blood count (CBC) test.

There is no one specific test to prove a patient has ITP. Instead, ITP is diagnosed by excluding other causes of a low platelet count. This includes making sure that the person does not have:

• HIV infection
• Hepatitis C infection
• Vitamin B12 or folate deficiencies
• A false low platelet count due to clumping of platelets in the blood collection tube

For certain individuals, additional testing can be performed to rule out:

• Helicobacter pylori infection
• Viral infections
• Myelodysplastic syndrome (especially if the patient is over the age of 60)

Occasionally, certain medications (including some over-the-counter medications), pregnancy or medical conditions, such as immune disorders or infections, will be associated with ITP. However, there is often no identifiable disease associated with ITP.

Reviewed by health care specialists at UCSF Medical Center.