What blood profile is most likely in a 5-year-old male with progressive swelling and redness after trauma, without a history of infection or malignancy?

Blood Profile Most Likely in a 5-Year-Old with Progressive Swelling After Trauma

The most likely blood profile in this 5-year-old male with progressive knee swelling and redness after trauma is option D: Normal PT, Increased PTT, Normal bleeding time, Normal platelet count.

Rationale for This Blood Profile

This case presents a classic picture of hemophilia, specifically hemophilia A (factor VIII deficiency) or hemophilia B (factor IX deficiency), which are characterized by:

• Progressive swelling that doesn't resolve with ice application
• Disproportionate response to minor trauma (bumping knee on sofa)
• No history of infection or malignancy
• Male patient (hemophilia is X-linked recessive)

Laboratory Findings in Hemophilia

In hemophilia, the coagulation profile typically shows:

1. Normal PT: The extrinsic pathway (measured by PT) remains intact because factors VII, X, V, II, and fibrinogen function normally 1

2. Increased PTT: The intrinsic pathway (measured by PTT) is prolonged due to deficiency in factor VIII (hemophilia A) or factor IX (hemophilia B) 1

3. Normal bleeding time: Primary hemostasis involving platelet function remains intact 1

4. Normal platelet count: Platelets are not affected in hemophilia 1

Hemophilia in Pediatric Patients

Hemophilia often presents in childhood with:

• Excessive bruising
• Prolonged bleeding after minor trauma
• Joint hemarthrosis (bleeding into joints)
• Soft tissue hematomas

The European guideline on management of major bleeding notes that "prolonged PT and aPTT, low levels of platelets and fibrinogen, and high levels of D-dimers" can be found in trauma patients with coagulopathy 1. However, in this case, the clinical picture strongly suggests an inherited coagulation disorder rather than trauma-induced coagulopathy.

Why Other Options Are Less Likely

• Option A (Increased PT, Normal PTT, Normal bleeding time, Normal platelet count): This pattern would suggest vitamin K deficiency or liver disease, which doesn't match the clinical presentation 1

• Option B (Normal PT, Normal PTT, Increased bleeding time, Decreased platelet count): This pattern suggests thrombocytopenia, which would be unlikely to cause isolated joint swelling after minor trauma 1

• Option C (Normal PT, Increased PTT, Increased bleeding time, Normal platelet count): While this shows the increased PTT consistent with hemophilia, the increased bleeding time is not typical of hemophilia alone 1

Clinical Implications

In pediatric patients with hemophilia presenting with joint swelling:

• Early factor replacement therapy is crucial to prevent long-term joint damage
• Target factor levels should be maintained above 50 × 10^9/l 1
• Careful monitoring for inhibitor development is essential

Common Pitfalls in Diagnosis

1. Mistaking hemophilia for child abuse due to excessive bruising
2. Attributing symptoms to normal childhood injuries
3. Failing to obtain family history (though many cases are spontaneous mutations)
4. Delaying treatment while awaiting factor assays

The progressive nature of swelling despite appropriate first aid (ice application) is a key clinical clue that should prompt consideration of an underlying bleeding disorder rather than a typical traumatic injury.