Evaluation of thrombocytopenia

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Última revisão: 29 Nov 2025

Última atualização: 22 Oct 2025

Thrombocytopenia is a low circulating platelet count, generally defined as <150,000 per microliter. Platelet life span is normally approximately 5 days, with continual renewal.

Thrombocytopenia results from either a reduced production of platelets in the bone marrow, increased clearance, sequestering of platelets in the spleen, or dilution.

The differential diagnosis for a patient with new thrombocytopenia is broad and includes primary bone marrow disorders, chronic liver disease, infection, drug-related adverse effects, occult malignancy, and autoimmune/rheumatologic conditions.

Epidemiology

The causes of thrombocytopenia are diverse, making epidemiologic generalizations difficult. However, immune thrombocytopenia (ITP) increases with age and has a slight female preponderance.[1][2] The apparent appearance of ITP in other patient groups should prompt a high index of suspicion for an alternate diagnosis: for example, non-Hodgkin lymphoma, drug effect, or myelodysplastic syndrome. ITP has an estimated incidence of approximately 2 to 5 cases per 100,000 in the general population.[1][2][3]

Investigation

A complete history, physical exam, review of the CBC, and peripheral smear are necessary to narrow down the differential diagnosis of thrombocytopenia. It is important to exclude artifact or pseudothrombocytopenia.[4]

Bone marrow biopsy and molecular testing for inherited thrombocytopenia and clonal myeloid neoplasms is performed if all other studies are inconclusive and a diagnosis of ITP is unlikely.

Primary ITP is diagnosed when there is no identifiable underlying condition following comprehensive patient evaluation.[4]

Diagnósticos diferenciais

comuns

Leukemia
Metastatic malignancy
Hodgkin lymphoma
Non-Hodgkin lymphoma
Miliary tuberculosis
Disseminated intravascular coagulation (DIC)
Post-transfusion
Hemolysis, elevated liver enzymes, low platelet count (HELLP)
Cardiopulmonary bypass
Immune thrombocytopenia (ITP)
Systemic lupus erythematosus (SLE)
Rheumatoid arthritis
Antiphospholipid syndrome
HIV/AIDS
Malaria
Dengue fever
Zika virus infection
Cytomegalovirus (CMV)
Infectious mononucleosis
COVID-19
Parvovirus B19
Sepsis
Heparin-induced thrombocytopenia (HIT)
Antimalarials, antiseizure drugs, antibiotics, or chemotherapies
Alcohol ingestion
B12 deficiency
Folate deficiency
Gestational thrombocytopenia
Cirrhosis

Detalhes completos

Incomuns

Multiple myeloma
Bone marrow fibrosis
Thrombotic thrombocytopenic purpura (TTP)
Hemolytic uremic syndrome (HUS)
Sarcoidosis
Cyclic thrombocytopenia
Wiskott-Aldrich syndrome
MYH9-related disorders, including May-Hegglin anomaly
Bernard-Soulier syndrome
Gaucher disease
Hashimoto thyroiditis
Aplastic anemia
Vaccinations
Paroxysmal nocturnal hemoglobinuria (PNH)
Pseudothrombocytopenia
Familial platelet disorder with germline RUNX1 mutation
Thrombocytopenia due to germline ANKRD26 mutation
Thrombocytopenia due to germline ETV6 mutation

Detalhes completos

Colaboradores

Autores

Hanny Al-Samkari, MD

Division of Hematology/Oncology

Peggy S. Blitz Endowed Chair in Hematology/Oncology

Massachusetts General Hospital

Associate Professor of Medicine

Harvard Medical School

Boston

Declarações

HA has received fees for consulting from Agios, Amgen, argenx, Alpine, Alnylam, Sobi, Pharmacosmos, Novartis and Sanofi; and received research funding to their institution from Amgen, Agios, Sobi, Novartis, and Vaderis.

Agradecimentos

Dr Hanny Al-Samkari would like to gratefully acknowledge Dr Julia T. Geyer and Dr Alan E. Lichtin, previous contributors to this topic. JTG declares that she has no competing interests. AEL is on an advisory board and has received research support from Amgen.

Revisores

Roger M. Lyons, MD, FACP

Clinical Professor of Medicine

University of Texas Health Science Center

San Antonio

Cancer Care Network of South Texas

San Antonio

Declarações

RML declares that he has no competing interests.

Jeffrey S. Wasser, MD

Clinical Assistant Professor of Medicine

University of Connecticut School of Medicine

Farmington

Declarações

JSW has received research support from Amgen, Ligand Pharmaceuticals, and MGI Pharma for clinical studies in immune thrombocytopenic purpura.

Keith R. McCrae, MD

Professor of Medicine

Case Western Reserve University School of Medicine

Cleveland

Declarações

KRM declares that he has no competing interests.

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Referências

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Principais artigos

Provan D, Arnold DM, Bussel JB, et al. Updated international consensus report on the investigation and management of primary immune thrombocytopenia. Blood Adv. 2019 Nov 26;3(22):3780-817.Texto completo Resumo

Cines DB, Levine LD. Thrombocytopenia in pregnancy. Blood. 2017 Nov 23;130(21):2271-7.Texto completo Resumo

American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 207: thrombocytopenia in pregnancy. Obstet Gynecol. 2019 Mar;133(3):e181-93. Resumo

Cooper N, Ghanima W. Immune thrombocytopenia. N Engl J Med. 2019 Sep 5;381(10):945-55.Texto completo Resumo

Evans L, Rhodes A, Alhazzani W, et al. Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021. Crit Care Med. 2021 Nov 1;49(11):e1063-143.Texto completo

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

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Evaluation of thrombocytopenia

Resumo

Epidemiology

Investigation

Diagnósticos diferenciais

comuns

Incomuns

Colaboradores

Autores

Hanny Al-Samkari, MD

Declarações

Agradecimentos

Revisores

Roger M. Lyons, MD, FACP

Declarações

Jeffrey S. Wasser, MD

Declarações

Keith R. McCrae, MD

Declarações

Créditos aos pareceristas

Declarações

Referências

Principais artigos

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

Folhetos informativos para os pacientes

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se para acessar todo o BMJ Best Practice