Residency · Residency · Pediatrics

Approach to Pediatric Bleeding and Coagulopathy

Introduction

Bleeding disorders in children range from common and benign (such as nosebleeds due to digital trauma) to rare and life-threatening (such as severe hemophilia with intracranial hemorrhage). A structured approach using clinical history, bleeding pattern recognition, and targeted laboratory testing is essential. Distinguishing between platelet/vascular disorders (which cause mucocutaneous bleeding) and coagulation factor deficiencies (which cause deep tissue and joint bleeding) guides the diagnostic workup and management.

Clinical Assessment

History

The bleeding history should address onset, duration, severity, triggers, and sites. Menstrual bleeding should be quantified, as heavy menstrual bleeding is the most common presenting symptom in adolescent girls with bleeding disorders. Family history may reveal an X-linked pattern (hemophilia), autosomal dominant inheritance (von Willebrand disease), or consanguinity. Surgical and dental history should be reviewed for excessive bleeding with procedures, circumcision, or tonsillectomy. Medication use including NSAIDs, aspirin, anticoagulants, and herbal supplements should be assessed. Validated bleeding assessment tools such as the ISTH Bleeding Assessment Tool (BAT) can be helpful, with a score of 3 or greater in children suggesting a bleeding disorder.

Bleeding Pattern Recognition

Mucocutaneous bleeding, which includes epistaxis, gingival bleeding, petechiae, purpura, easy bruising, menorrhagia, and GI bleeding, suggests a platelet or vascular disorder. Deep tissue and musculoskeletal bleeding, characterized by hemarthroses, muscle hematomas, delayed post-surgical bleeding, and intracranial hemorrhage, points toward a coagulation factor deficiency. Some disorders, such as severe von Willebrand disease, produce a combined pattern.

Initial Laboratory Evaluation

The initial workup should include a CBC with platelet count to assess for thrombocytopenia, and a peripheral blood smear to evaluate platelet size and morphology (large platelets in Bernard-Soulier syndrome, small platelets in Wiskott-Aldrich syndrome) and to look for schistocytes (TTP/HUS). The PT (prothrombin time)/INR evaluates the extrinsic and common pathways (factors VII, X, V, II, and fibrinogen), while the aPTT (activated partial thromboplastin time) evaluates the intrinsic and common pathways (factors XII, XI, IX, VIII, X, V, II, and fibrinogen). A fibrinogen level and thrombin time should also be obtained. If the PT or aPTT is prolonged, a mixing study determines whether correction occurs with normal plasma (suggesting factor deficiency) or does not correct (suggesting an inhibitor such as lupus anticoagulant or a factor-specific inhibitor).

<image>Coagulation cascade diagram showing intrinsic (aPTT) and extrinsic (PT) pathways converging at the common pathway, with each factor labeled and clinical conditions associated with deficiency of specific factors highlighted</image>

Platelet Disorders

Quantitative (Thrombocytopenia)

Immune thrombocytopenia (ITP) is the most common cause of isolated thrombocytopenia in children, with a peak age of 2-5 years and onset often following a viral infection. It presents as isolated thrombocytopenia (platelets often less than 20,000) with an otherwise normal CBC and smear showing large platelets. Importantly, 80% of childhood ITP resolves spontaneously within 6-12 months. Treatment decisions should be based on bleeding symptoms rather than platelet count alone: observation is appropriate for mild symptoms, while IVIG (1 g/kg for 1-2 doses), corticosteroids (prednisone 1-2 mg/kg/day for 5-7 days), or anti-D immunoglobulin (in Rh-positive, non-splenectomized patients) can be used for significant bleeding. Chronic ITP lasting longer than 12 months may warrant thrombopoietin receptor agonists (eltrombopag, romiplostim), rituximab, or splenectomy.

Neonatal alloimmune thrombocytopenia (NAIT) results from maternal antibodies against fetal platelet antigens, most commonly HPA-1a, and carries a risk of intracranial hemorrhage. Treatment includes IVIG and antigen-negative platelets. Other causes of thrombocytopenia include bone marrow failure (aplastic anemia, leukemia), infections (EBV, HIV, HCV), drug-induced thrombocytopenia, and thrombotic microangiopathies (HUS, TTP).

Qualitative (Platelet Function Disorders)

Inherited platelet function disorders include Glanzmann thrombasthenia (GPIIb/IIIa deficiency), Bernard-Soulier syndrome (GPIb/IX/V deficiency), and storage pool deficiency. Acquired causes include medications (NSAIDs, aspirin), uremia, and cardiopulmonary bypass. Screening with the PFA-100 (platelet function analyzer) can identify prolonged closure time suggesting platelet dysfunction, with confirmation by platelet aggregation studies.

Coagulation Factor Deficiencies

Von Willebrand Disease (VWD)

Von Willebrand disease is the most common inherited bleeding disorder, with a prevalence of approximately 1%. Von Willebrand factor (VWF) mediates platelet adhesion and serves as a carrier for factor VIII. Type 1 accounts for 80% of cases and represents a partial quantitative deficiency inherited in an autosomal dominant pattern, causing mild to moderate bleeding. Type 2, which comprises 15-20% of cases, involves qualitative defects with subtypes 2A, 2B, 2M, and 2N. Type 3 is rare and involves complete absence of VWF, causing severe bleeding including hemarthroses.

Diagnosis requires measurement of VWF antigen, VWF activity (ristocetin cofactor), factor VIII level, and VWF multimer analysis. Treatment options include desmopressin (DDAVP) as first-line therapy for type 1, which releases VWF from endothelial stores (a DDAVP challenge test should be performed before clinical use); VWF-containing factor concentrates (Humate-P, Wilate) for type 2, type 3, or DDAVP-unresponsive type 1; tranexamic acid as an adjunctive antifibrinolytic for mucosal bleeding; and hormonal therapy with combined oral contraceptives for menorrhagia.

Hemophilia A and B

Hemophilia A is factor VIII deficiency, inherited in an X-linked recessive pattern, with an incidence of 1 in 5,000 male births. Hemophilia B is factor IX deficiency, also X-linked recessive, with an incidence of 1 in 30,000 male births. Severity is classified by factor level: severe (less than 1%) with spontaneous bleeding and hemarthroses, moderate (1-5%) with bleeding from minor trauma, and mild (5-40%) with bleeding only with surgery or significant trauma. Diagnosis shows a prolonged aPTT with normal PT, and specific factor assays provide confirmation.

Treatment includes factor replacement given on-demand for acute bleeds and as prophylactic infusions for severe hemophilia (the standard of care to prevent joint disease). Extended half-life factor products reduce infusion frequency. Emicizumab, a bispecific antibody that mimics factor VIIIa function, is administered subcutaneously and has revolutionized hemophilia A prophylaxis, with effectiveness even in patients with inhibitors. Inhibitor development is the most serious treatment complication, occurring in 20-30% of severe hemophilia A cases, and is managed with bypassing agents (rFVIIa, aPCC) and immune tolerance induction.

<image>Clinical comparison showing mucocutaneous bleeding pattern (petechiae, epistaxis, gingival bleeding, menorrhagia) characteristic of platelet disorders versus deep tissue bleeding pattern (hemarthrosis, muscle hematoma, post-surgical bleeding) characteristic of coagulation factor deficiencies, with associated laboratory findings</image>

Acquired Coagulopathies

Vitamin K deficiency bleeding (VKDB) occurs in early (day 1), classic (days 2-7), or late (2-12 weeks) forms and is prevented by intramuscular vitamin K at birth. Risk factors for late VKDB include exclusive breastfeeding and cholestatic liver disease. Disseminated intravascular coagulation (DIC) occurs in the setting of sepsis, malignancy, or trauma and presents as a consumptive coagulopathy with prolonged PT/aPTT, low fibrinogen, elevated D-dimer, thrombocytopenia, and schistocytes; treatment centers on the underlying cause. Liver disease results in reduced synthesis of all clotting factors except factor VIII and VWF.

<image>Flowchart for evaluation of a child with suspected bleeding disorder starting with bleeding history and pattern, proceeding through initial screening labs (CBC, PT, aPTT, fibrinogen), and branching into specific diagnostic pathways based on results</image>

Clinical Pearls

A normal PT and aPTT do not exclude a bleeding disorder. Von Willebrand disease, the most common inherited bleeding disorder, often has normal screening tests, and factor XIII deficiency also presents with normal PT and aPTT. ITP in children is usually self-limited, and treatment decisions should be based on bleeding symptoms rather than platelet count alone. Every newborn should receive intramuscular vitamin K at birth, as parental refusal is a risk factor for life-threatening late VKDB. Hemarthrosis in a male child is hemophilia until proven otherwise, and factor replacement should not be delayed pending lab confirmation. Heavy menstrual bleeding at menarche warrants screening for bleeding disorders, as up to 20% of adolescents presenting with menorrhagia have an underlying disorder, most commonly VWD.

References

1. Flood VH, Christopherson PA, Gill JC, et al. Clinical and Laboratory Variability in a Cohort of Patients Diagnosed with Type 1 VWD in the United States. Blood. 2016;127(20):2481-2488.
2. Srivastava A, Santagostino E, Dougall A, et al. WFH Guidelines for the Management of Hemophilia, 3rd Edition. Haemophilia. 2020;26(Suppl 6):1-158.
3. Neunert C, Terrell DR, Arnold DM, et al. American Society of Hematology 2019 Guidelines for Immune Thrombocytopenia. Blood Adv. 2019;3(23):3829-3866.
4. Rodeghiero F, Tosetto A, Abshire T, et al. ISTH/SSC Bleeding Assessment Tool: A Standardized Questionnaire and a Proposal for a New Bleeding Score for Inherited Bleeding Disorders. J Thromb Haemost. 2010;8(9):2063-2065.

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