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Pediatric Bleeding: ITP, Hemophilia & Vitamin K Deficiency

Name: Pediatric Bleeding: ITP, Hemophilia & Vitamin K Deficiency
Creator: Veli Bakalov, MD

Surface bleeding points to platelets; deep bleeding points to factors

Pediatrics·Hematology & Oncology·4 min read·8 high-yield points·Reviewed by Veli Bakalov, MD @HemeOncBuddy

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Petechiae and mucosal bleeding point to platelets or von Willebrand factor; hemarthroses and deep muscle hematomas point to a clotting factor deficiency.
ITP: well child 1–4 weeks after a viral illness with isolated thrombocytopenia, large platelets, and no organomegaly.
ITP with skin-only bleeding → observe regardless of platelet count; mucosal bleeding → short prednisone course first, IVIG when a rapid rise is needed, or anti-D; chronic if >12 months.
Bone pain, hepatosplenomegaly, lymphadenopathy, or other cytopenias with thrombocytopenia → bone marrow exam for leukemia.
Hemophilia A/B: X-linked, isolated prolonged PTT that corrects on mixing → factor VIII/IX replacement (before CT after head trauma), emicizumab prophylaxis, no IM injections or NSAIDs.
von Willebrand disease: epistaxis, bruising, and heavy menses from menarche → desmopressin for type 1.
Vitamin K deficiency bleeding: prolonged PT with normal platelets; late form at 2–12 weeks in breastfed infants who missed IM vitamin K causes intracranial hemorrhage → IV vitamin K plus FFP.
Bruising on the torso, ears, or neck in a young child, or any bruise in a pre-mobile infant → abuse evaluation.

Approach to the bleeding child

Read the pattern. Defects of platelets or von Willebrand factor (primary hemostasis) cause petechiae, purpura, and mucosal bleeding such as epistaxis, gum bleeding, and heavy menses, appearing immediately after injury. Clotting factor deficiencies (secondary hemostasis) cause deep, delayed bleeding: hemarthroses, muscle hematomas, and oozing hours after circumcision or surgery. The first tests are a CBC with smear, PT/INR, and PTT.

Screening labs in pediatric bleeding

Disorder	Platelets	PT	PTT
ITP	Low (isolated)	Normal	Normal
Hemophilia A/B	Normal	Normal	Prolonged, corrects on mixing
von Willebrand disease	Normal	Normal	Normal or mildly prolonged
Vitamin K deficiency	Normal	Prolonged first	Normal or prolonged
DIC	Low	Prolonged	Prolonged; low fibrinogen

Immune thrombocytopenia

Presentation. ITP peaks at ages 2–5, typically 1–4 weeks after a viral illness. IgG autoantibodies against platelet glycoprotein IIb/IIIa lead to splenic destruction, producing sudden petechiae, purpura, and bruising in an otherwise well child. Only the platelets are low, often below 20,000/µL; hemoglobin, white count, and differential are normal, the smear shows large platelets without blasts, and there is no lymphadenopathy, hepatosplenomegaly, or bone pain.

Management. Children with no bleeding or skin-only bleeding are observed regardless of the platelet count, with avoidance of contact sports, aspirin, and NSAIDs. Mucosal or other significant bleeding is treated with a short course of prednisone (preferred first by ASH 2019), IVIG when a rapid rise is needed (the fastest rise), or anti-D immunoglobulin, which is used only in Rh-positive children with an intact spleen and no anemia because it causes hemolysis. Intracranial hemorrhage occurs in under 1% and is treated with platelet transfusion plus IVIG and IV methylprednisolone.

When to examine the marrow. Typical ITP does not need a bone marrow exam. Atypical features demand one: bone pain or limp, fever, weight loss, lymphadenopathy, hepatosplenomegaly, other cytopenias, or blasts, which suggest ALL or aplastic anemia. Wiskott-Aldrich syndrome (boys with eczema and small platelets), HUS, and SLE in adolescents are other considerations.

Course. Roughly 3 in 4 children recover within 12 months. ITP is termed newly diagnosed under 3 months, persistent at 3–12 months, and chronic beyond 12 months; chronicity is likelier in adolescents and with insidious onset. Options for chronic ITP include thrombopoietin receptor agonists (eltrombopag, romiplostim), rituximab, and rarely splenectomy. An adolescent girl with chronic ITP should be screened for SLE.

Hemophilia and von Willebrand disease

Hemophilia. Hemophilia A (factor VIII, about 80–85% of cases) and hemophilia B (factor IX) are X-linked recessive, so boys are affected, and about one-third of cases arise from new mutations. Severity follows factor activity: severe below 1%, moderate 1–5%, mild 5–40%. Clues include circumcision bleeding, bruising once crawling begins, hemarthroses of the knees, elbows, and ankles that lead to chronic arthropathy, deep muscle hematomas, and intracranial hemorrhage.

Diagnosis. Only the PTT is prolonged; PT, platelet count, and platelet function are normal. A 1:1 mixing study corrects a factor deficiency (VIII, IX, or XI) but not an inhibitor such as an acquired factor VIII antibody or lupus anticoagulant. Specific factor VIII and IX assays confirm the type and severity.

Treatment. Bleeds are treated promptly with factor VIII or IX concentrate. Desmopressin helps mild hemophilia A, and antifibrinolytics (tranexamic or aminocaproic acid) help mucosal bleeding. Prophylaxis uses regular factor infusions or, for hemophilia A, subcutaneous emicizumab, a bispecific antibody that bridges factors IXa and X. About 30% of patients with severe hemophilia A develop inhibitors, managed with bypassing agents (recombinant factor VIIa, aPCC), emicizumab, or immune tolerance induction.

After head trauma in hemophilia, give factor before the CT. Avoid IM injections, aspirin, and NSAIDs, and do not aspirate a hemophilic joint for diagnosis.

von Willebrand disease. The most common inherited bleeding disorder, usually autosomal dominant type 1. Deficient vWF impairs platelet adhesion and shortens factor VIII survival, causing epistaxis, easy bruising, bleeding after dental work or tonsillectomy, and heavy menstrual bleeding from menarche. Testing includes vWF antigen, vWF activity, and factor VIII; the PTT may be normal or mildly prolonged. Type 1 is treated with desmopressin, with tranexamic acid or hormonal therapy for heavy menses.

Vitamin K deficiency bleeding

Why newborns are vulnerable. Placental transfer of vitamin K is poor, the newborn gut is sterile, and breast milk contains little, so factors II, VII, IX, and X run low.

Early (≤24 hours): maternal anticonvulsants, rifampin, isoniazid, or warfarin; cephalohematoma, intracranial or GI bleeding
Classic (days 2–7): GI, umbilical stump, or circumcision bleeding
Late (2–12 weeks): exclusively breastfed infants who missed prophylaxis or have cholestasis; often intracranial hemorrhage

Diagnosis and treatment. The PT prolongs first because factor VII has the shortest half-life; the PTT may follow, while platelets and fibrinogen stay normal, unlike DIC. Treat with IV vitamin K plus FFP or prothrombin complex concentrate for serious bleeding. A single IM dose of vitamin K at birth prevents nearly all cases, and parental refusal is now the main risk factor.

When bruising suggests abuse

Red-flag bruises. Bruising on the torso, ears, or neck in a child under 4 years, any bruise in an infant under 4 months, and injuries to the frenulum, angle of the jaw, cheeks, eyelids, or subconjunctivae, or patterned marks (the TEN-4-FACESp rule), should prompt an abuse evaluation: skeletal survey, head imaging as indicated, and a report to child protective services. A bleeding disorder screen (CBC, PT, PTT, vWF studies) runs in parallel, but a coagulopathy does not exclude abuse.