Most patients with ITP are asymptomatic. In those who develop symptoms, symptoms are related to thrombocytopenia and bleeding. Onset of symptoms is more often insidious but can also occur abruptly. Bleeding can occur in up to two-thirds of patients. It typically occurs in the skin or mucous membranes. This pattern of bleeding is referred to as "platelet-type" bleeding. Skin manifestations include petechiae and purpura. Petechiae are flat, red, and discrete lesions that do not blanch under pressure. Petechiae are usually found in the dependent areas of the body (legs and sacral areas). Purpura can also be seen and consists of a coalescence of petechiae. If purpura involves the skin, it is referred to as dry purpura. If it involves the mucous membranes, it is referred to as wet purpura. Wet purpura is a more concerning finding because it predicts more severe bleeding.
Patients can also experience minimal epistaxis, for example with nose blowing. Continuous epistaxis is less common; however, if it occurs, it requires immediate attention and intervention. Severe hemorrhage such as intracranial bleeding or gastrointestinal bleeding is relatively uncommon in patients with ITP but may still occur. Patients with platelet counts < 10,000/µL to < 20,000/µL and those with wet purpura are at higher risk for more severe bleeding.
ITP is a diagnosis of exclusion made in patients with isolated thrombocytopenia without anemia or leukopenia. Excluding other causes of thrombocytopenia before a diagnosis of ITP is made is important, as is identifying the presence of any underlying conditions that may be responsible for secondary ITP. A thorough history, physical examination, and review of the complete blood count (CBC) findings are important. History of recent infections, use of certain medications, and the presence of rheumatological or hematological disorders must be reviewed. Asking about tonic water ingestion (a source of quinine), herbal remedies, and dietary habits is also important. Quinine is known to be associated with ITP. History should also focus on bleeding symptoms and family history of bleeding disorders. Physical examination should focus on skin and oral mucous membranes. Investigation for lymphadenopathy and hepatosplenomegaly is crucial, as this may point to an underlying condition.
A CBC, peripheral blood smear, coagulation studies, and HIV and HCV testing should be obtained. A CBC and peripheral blood smear can help confirm the diagnosis by excluding abnormalities in the other cell lines. A peripheral blood smear is important to ensure the thrombocytopenia is not secondary to platelet clumping (pseudothrombocytopenia). WBCs and RBCs should have normal morphology. Megakaryocytes can be seen in patients with ITP on blood smears. Coagulation studies are normal in patients with ITP. Other testing should be done if the clinical presentation is suggestive of secondary causes of ITP. Patients with gastrointestinal symptoms may have Helicobacter pylori testing. Those with symptoms of hypothyroidism or hyperthyroidism should be tested for thyroid abnormalities. Antinuclear antibody testing may be performed if the patient is suspected to have SLE. A bone marrow examination should be performed only if other unexplained cytopenias are present, if dysplasia is noted on the peripheral blood smear, or if platelet counts do not respond to ITP therapy.
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Cite this: Basma Abdulhadi. Emergency Medicine Case Challenge: Bleeding Gums and Rash on Both Legs in a 38-Year-Old Man - Medscape - Apr 12, 2023.