Examkin

Soru

Zorluk: KolayFormulating a Differential Diagnosis

A 28-year-old woman comes to the clinic reporting a 3-day history of unprovoked nosebleeds and a new rash on her legs. She reports having a mild viral upper respiratory infection two weeks ago but otherwise feels well. She takes no medications and has no family history of bleeding disorders. Her vital signs are within normal limits. Physical examination reveals scattered, pinpoint, red, non-blanching macules on her bilateral lower extremities. There is no lymphadenopathy or hepatosplenomegaly. Laboratory evaluation reveals:

Hemoglobin: 13.2 g/dL
Leukocyte count: 7,200/mm³
Platelet count: 18,000/mm³
Prothrombin time (PT): 12 seconds
Partial thromboplastin time (PTT): 28 seconds

Based on the clinical presentation and laboratory findings, which of the following is the most likely diagnosis?

  1. Immune thrombocytopeniaCevap
  2. B
    Disseminated intravascular coagulation
  3. C
    Thrombotic thrombocytopenic purpura
  4. D
    Von Willebrand disease
  5. E
    Acute myeloid leukemia

Cevap

Immune thrombocytopenia
The correct diagnosis is immune thrombocytopenia (ITP). This patient presents with signs of primary hemostasis dysfunction, specifically mucocutaneous bleeding (epistaxis and petechiae). The laboratory findings show isolated thrombocytopenia with a normal hemoglobin level, normal leukocyte count, and normal coagulation studies (PT and PTT). In an otherwise healthy adult, this clinical picture, especially following a recent viral illness, is highly characteristic of ITP, which is caused by autoantibodies directed against platelet surface antigens.

Adım Adım Çözüm

1
Analyze the patient's symptoms and physical examination findings.
The patient has epistaxis and petechiae (pinpoint, non-blanching red macules), which are signs of primary hemostasis defects (platelet disorders). There is no hepatosplenomegaly.
Differentiates between primary hemostasis (platelet) and secondary hemostasis (coagulation factor) issues.
2
Interpret the laboratory results.
The patient has isolated severe thrombocytopenia (18,000/mm³). Hemoglobin, leukocyte count, PT, and PTT are all normal.
Helps narrow down the differential diagnosis of bleeding disorders.
3
Synthesize the clinical picture with the laboratory data to formulate the most likely diagnosis.
A recent viral infection followed by isolated thrombocytopenia and mucocutaneous bleeding in an otherwise healthy adult points directly to immune thrombocytopenia (ITP).
Identifies the classic presentation of the correct diagnosis.

Anahtar Kavram

Patients with immune thrombocytopenia typically present with mucocutaneous bleeding and isolated thrombocytopenia, often following a viral infection, with normal coagulation studies (PT and PTT).
Bu soruyu puanla

Konular

Formulating a Differential Diagnosis

Bu konudan daha fazla soru