Idiopathic thrombocytopenic purpura (ITP) is a rare bleeding disorder that causes excessive bleeding and bruising due to an insufficient amount of platelets—cells that clump together to form a blood clot.
Diagnosing ITP requires an in-depth process, as it is possible for the condition to show no symptoms. Even if symptoms do occur, they bear a resemblance to other blood disorders or types of cancer. A doctor must rule out other conditions first; therefore, diagnosis is seen more as a process of elimination. Here is an overview of what the diagnostics process for ITP entails.
First Steps
The first step of diagnosis begins with you preparing for the consultation. Make a list of current medications, as well as symptoms you are experiencing, and any questions you may have. This list will be beneficial to your doctor, as certain medications, such as blood thinners, chemotherapy drugs, or seizure medication, can destroy or prevent the production platelets, thus causing ITP.
Exclusion Process
ITP is diagnosed by excluding other possible causes. First, a doctor will determine that low platelet count is the only blood abnormality and that the only physical sign is bleeding. After this is determined, the doctor will go on to exclude other underlying causes or illnesses that affect bleeding, like leukemia or HIV. These are a few examples of what a doctor will look for during the process.
Tests
A complete blood count (CDC) test is used to evaluate the total number of white and red blood cells and platelets in a blood sample. Another possible blood test used in diagnosing ITP is a blood smear. A sample of blood is placed on a slide and studied under a microscope. The test is done to identify the number of platelets.
After blood tests, the next step is a bone marrow biopsy or aspiration to evaluate the production of megakaryocytes, which are platelet-forming cells. A person with ITP will show an increase in production of megakaryocytes. A bone marrow sample also helps rule out other conditions, such as metastatic cancer and leukemia.
Following diagnosis, another blood test will be done to look for other conditions associated with ITP, such as lupus or infection.
