Thrombotic thrombocytopenic purpura

Last reviewed: 23 Aug 2023
Last updated: 16 Mar 2022



History and exam

Key diagnostic factors

  • nonspecific prodrome
  • severe neurologic symptoms (coma, focal abnormalities, seizures)
  • mild neurologic symptoms (headache, confusion)
  • fever
More key diagnostic factors

Other diagnostic factors

  • age 30 to 50 years
  • digestive symptoms (nausea, vomiting, diarrhea, abdominal pain)
  • weakness
  • bleeding symptoms (purpura, ecchymosis, menorrhagia)
Other diagnostic factors

Risk factors

  • black ethnicity
  • female gender
  • obesity
  • pregnancy (near term or postpartum period)
  • cancer therapies
  • HIV infection
  • bone marrow transplantation
  • antiplatelet agents
  • quinine
More risk factors

Diagnostic investigations

1st investigations to order

  • platelet count
  • hemoglobin
  • haptoglobin
  • peripheral smear
  • reticulocyte count
  • urinalysis
  • BUN and creatinine
  • direct Coombs test
More 1st investigations to order

Investigations to consider

  • ADAMTS-13 activity assay and inhibitor titers
More investigations to consider

Treatment algorithm


acquired (idiopathic) TTP: acute episode


acquired (idiopathic) TTP: following resolution of acute episode



Sandeep K. Rajan, MD

Associate Professor of Medicine

Division of Hematology and Medical Oncology

Vanderbilt University




SKR has received honoraria for advisory consultancy and speakers bureau, and received research funds from Alexion, Novo-Nordisk, Sanofi and Appelis.


Dr Sandeep K. Rajan would like to gratefully acknowledge Dr Rebecca Fischer Connor, a previous contributor to this topic.


RFC declares that she has no competing interests.

Peer reviewers

James N. George, MD

George Lynn Cross Professor

Department of Biostatistics and Epidemiology

University of Oklahoma Health Sciences Center

Oklahoma City



JNG declares that he has no competing interests.

Christoph Pechlaner, MD

Associate Professor of Medicine

Department of Internal Medicine

Innsbruck Medical University




CP declares that he has no competing interests.

  • Thrombotic thrombocytopenic purpura images
  • Differentials

    • Hemolytic uremic syndrome (HUS)
    • Atypical hemolytic uremic syndrome (aHUS)
    • Hypertension, malignant
    More Differentials
  • Guidelines

    • ISTH guidelines for the diagnosis of thrombotic thrombocytopenic purpura
    • Guidelines on the diagnosis and management of thrombotic thrombocytopenic purpura and other thrombotic microangiopathies
    More Guidelines
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer