10.2 Pediatric Bleeding Disorders: Hemophilia A/B & Immune Thrombocytopenia

Pediatric Bleeding Disorders: Hemophilia A/B & Immune Thrombocytopenia

Quick Overview: Hemostatic disorders in pediatrics are fundamentally categorized into secondary hemostatic defects (clotting factor deficiencies such as Hemophilia A and B) and primary hemostatic defects (platelet disorders such as Immune Thrombocytopenia). Hemophilia A (Factor VIII deficiency) and Hemophilia B (Factor IX deficiency) are X-linked recessive coagulopathies that manifest with deep tissue hematomas and crippling hemarthroses, characterized by an isolated prolonged activated partial thromboplastin time (aPTT). Conversely, Immune Thrombocytopenia (ITP) represents an acute, post-viral autoimmune clearance of circulating platelets by splenic macrophages, presenting with isolated thrombocytopenia and superficial cutaneous petechiae. On the ANCC PED-BC examination, pediatric nurses must excel in differentiating these pathways, initiating urgent factor replacement, implementing safe injection techniques, and enforcing strict medication contraindications.

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1. Hemophilia A & B: Genetics, Severity & Coagulation Cascade

Hemophilia represents the most common severe inherited congenital bleeding disorder. It is caused by mutations in the genes encoding essential blood coagulation factors within the intrinsic pathway of the coagulation cascade.

Types & Coagulation Factor Deficiencies

• Hemophilia A ("Classic Hemophilia"): Deficiency or absence of Factor VIII. Accounts for approximately 80% to 85% of all hemophilia cases (prevalence: ~1 in 5,000 male live births).
• Hemophilia B ("Christmas Disease"): Deficiency or absence of Factor IX. Accounts for approximately 15% to 20% of all hemophilia cases (prevalence: ~1 in 25,000 to 30,000 male live births).
• Clinical Note: Hemophilia A and Hemophilia B are clinically indistinguishable in their manifestations and physical presentation; differentiation relies entirely on specific quantitative factor assays.

Genetic Transmission: X-Linked Recessive Inheritance

Both the F8 and F9 genes are situated on the long arm of the X chromosome (Xq28 and Xq27):

• Males (XY): Hemizygous for the X chromosome. Inheriting a single mutant allele results in clinical disease. Males cannot transmit the disease to their sons (who inherit their father's normal Y chromosome).
• Carrier Females (XX): Heterozygous females have one mutated and one normal X chromosome. They generally possess ~50% factor activity and are asymptomatic carriers. However, due to extreme lyonization (skewed X-chromosome inactivation), a minority of carriers exhibit mild bleeding symptoms with factor levels < 40%.
• Inheritance Patterns:
  • Mother is a carrier, Father is unaffected: 50% chance each son has hemophilia; 50% chance each daughter is a carrier.
  • Father has hemophilia, Mother is unaffected: 100% of daughters are obligate carriers; 0% of sons are affected.
  • Spontaneous Mutation: Approximately 30% of new hemophilia cases arise from de novo spontaneous genetic mutations without any antecedent family history.

Clinical Severity Classification Based on Factor Activity

Normal circulating factor VIII or IX coagulant activity ranges between 50% and 150% (0.50 to 1.50 IU/mL):

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2. Laboratory Profile & The Coagulation Pathway

Understanding the laboratory profile of hemophilia is a bedrock ANCC exam competency:

Coagulation Testing in Hemophilia:
├── aPTT (Activated Partial Thromboplastin Time): MARKEDLY PROLONGED (Tests Intrinsic Pathway: XII, XI, IX, VIII, X, V, II, I)
├── PT / INR (Prothrombin Time / International Normalized Ratio): COMPLETELY NORMAL (Tests Extrinsic Pathway: VII, Common)
├── Platelet Count: COMPLETELY NORMAL (Primary hemostasis intact; normal 150,000 - 450,000/mcL)
├── Bleeding Time / PFA-100: NORMAL (Platelet plug formation and adhesion are normal)
├── Thrombin Time & Fibrinogen: NORMAL (Conversion of fibrinogen to fibrin is intact)
└── Specific Factor Assay (Factor VIII or IX): DIAGNOSTIC (Directly measures depressed factor percentage)

• Prolonged aPTT: Because Factors VIII and IX are essential enzymatic cofactors within the intrinsic tenase complex (Factor IXa + Factor VIIIa + phospholipid + calcium) that activates Factor X, intrinsic pathway clot formation is critically delayed, resulting in a significantly prolonged aPTT.
• Normal PT / INR: The extrinsic tissue factor pathway (Factor VIIa + Tissue Factor) is completely unimpaired; therefore, the Prothrombin Time is normal.
• Normal Platelet Count & Normal Bleeding Time: Primary hemostasis (platelet adhesion to exposed collagen and formation of the initial unstable platelet plug) is fully functional. Patients bleed not because they fail to form an initial plug, but because they cannot generate sufficient thrombin to cross-link fibrin, causing the platelet plug to disintegrate prematurely.

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3. Clinical Manifestations of Hemophilia: Hemarthrosis & Life-Threatening Hemorrhage

1. Hemarthrosis (Bleeding into Synovial Joint Cavities)

Hemarthrosis represents the hallmark clinical manifestation of severe hemophilia, accounting for 70% to 80% of all bleeding episodes:

• Most Commonly Affected Joints (Hinge Joints): Knees (~45%), elbows (~30%), ankles (~15%), shoulders, and hips.
• Aura & Early Symptoms: Children frequently describe an internal "aura"—a tingling, tickling, bubbling, or prickling sensation within the joint space, accompanied by subtle warmth, preceding visible objective swelling.
• Established Hemarthrosis Signs: Intense throbbing pain, tense swelling, severe erythema, local heat, marked restriction of range of motion, and held flexion contracture. The child holds the extremity immobilized and refuses to bear weight.
• Long-Term Chronic Complication (Hemophilic Arthropathy): Recurrent intra-articular bleeding deposits toxic hemosiderin (iron) into the synovial membrane, triggering chronic inflammatory proliferative synovitis. Synovial hypertrophy promotes hypervascularity, creating a vulnerable "target joint" prone to repeated spontaneous bleeds. This causes progressive destruction of articular cartilage, subchondral cyst formation, bone erosion, severe joint deformities, muscle atrophy, and crippling chronic pain.

2. Deep Intramuscular Hematomas

Bleeding into large muscle compartments (e.g., gastrocnemius, quadriceps, forearm, or iliopsoas muscle). An iliopsoas hematoma presents insidiously with severe lower abdominal or groin pain, trunk flexion with inability to extend the hip, and paresthesias along the anterior thigh due to femoral nerve compression. Significant intramuscular bleeding can precipitate compartment syndrome, causing neuromuscular necrosis.

3. Life-Threatening Intracranial Hemorrhage (ICH)

Intracranial hemorrhage represents the leading cause of death from bleeding in children with hemophilia:

• Can occur spontaneously in neonates or following minor, seemingly trivial head bumps or falls in toddlers.
• Symptoms: Irritability, persistent lethargy, headache, projectile vomiting, pupil asymmetry, drowsiness, seizures, or coma.
• MANDATORY CLINICAL DIRECTIVE: In ANY child with hemophilia who sustains head trauma or exhibits neurological symptoms, ADMINISTER FULL-DOSE FACTOR CONCENTRATE IMMEDIATELY BEFORE OBTAINING A HEAD CT SCAN! Never delay lifesaving factor infusion while arranging imaging.

4. Other Bleeding Manifestations

Prolonged bleeding following circumcision or umbilical cord separation in neonates; extensive oral mucosal bleeding following frenulum tears or erupting deciduous teeth; spontaneous microscopic or gross hematuria; and retropharyngeal/neck hematomas causing airway compromise.

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4. Comprehensive Hemophilia Management & Nursing Precautions

Therapeutic management combines immediate factor replacement, conservative orthopedic stabilization, strict medication safety, and proactive injury prevention.

Primary Pharmacotherapy: Factor Replacement Protocols

1. Intravenous Clotting Factor Concentrates:
   • Recombinant Factor VIII or IX: Genetically engineered concentrates free of human plasma donors; preferred first-line therapy to eliminate the risk of blood-borne viral transmission (HIV, hepatitis B/C).
   • Plasma-Derived Concentrates: Highly purified and viral-inactivated; utilized when recombinant products are unavailable.
   • Dosing Standards:
     • 1 IU of Factor VIII per kg body weight raises plasma Factor VIII activity by 2% (0.02 IU/mL).
     • 1 IU of Factor IX per kg body weight raises plasma Factor IX activity by 1% (0.01 IU/mL).
     • Severe life-threatening bleeds (ICH, major trauma, surgical procedures) require raising factor levels to 80% to 100% of normal activity.
     • Mild-to-moderate hemarthroses require raising factor levels to 40% to 50%.
2. Therapeutic Regimens:
   • Prophylactic Therapy: Regular routine IV infusions of factor concentrate (2 to 3 times weekly for Factor VIII; 1 to 2 times weekly for Factor IX) initiated in young children with severe hemophilia to maintain trough factor activity > 1% to 2%, preventing spontaneous hemarthroses and chronic arthropathy.
   • On-Demand Therapy: Administered immediately at the first sign or suspicion of bleeding, or prior to scheduled dental/surgical procedures.
3. Desmopressin (DDAVP):
   • Synthetic analogue of antidiuretic hormone that triggers rapid exocytosis of endogenous Factor VIII and von Willebrand factor stored within endothelial cell Weibel-Palade bodies.
   • CLINICAL INDICATION LIMIT: Indicated ONLY for mild Hemophilia A (baseline Factor VIII > 5%).
   • STRICT INEFFECTIVENESS: DDAVP is COMPLETELY INEFFECTIVE in severe Hemophilia A (no endogenous storage) and USELESS in Hemophilia B (Factor IX synthesis is entirely independent of endothelial storage and vasopressin receptors!).
   • Route: Intravenous (0.3 mcg/kg infused over 20–30 minutes) or concentrated high-dose intranasal spray (Stimate).
   • Fluid safety: Strict fluid restriction for 24 hours post-dose to prevent dilutional hyponatremia and water intoxication.
4. Antifibrinolytic Agents (Aminocaproic Acid / Tranexamic Acid):
   • Competitive inhibitors of plasminogen activation that stabilize formed fibrin clots.
   • Highly effective adjuncts for mucosal and oral bleeding (e.g., dental extractions, epistaxis). Caution: Contraindicated in patients with upper urinary tract hematuria due to the risk of creating obstructive ureteral clots.

Acute Hemarthrosis Nursing Care: The R.I.C.E. Protocol

When a child presents with acute joint hemarthrosis, implement this structured emergency protocol:

1. Factor Concentrate Infusion: Administer IV recombinant factor immediately. Factor replacement is the definitive hemostatic priority!
2. R.I.C.E. Protocol Implementation:
   • Rest / Immobilization: Rest the affected joint. Splint or immobilize the limb in a functional, slightly flexed position during active bleeding to prevent mechanical strain.
   • Ice / Cold Application: Apply cold packs or ice wrapped in a cloth to the joint for 15 to 20 minutes every 2 to 4 hours. Cold induces local vasoconstriction, limits hematoma expansion, and numbs pain. HEAT APPLICATION IS STRICTLY FORBIDDEN, as heat promotes vasodilation and accelerates intra-articular bleeding!
   • Compression: Apply an elastic compression bandage (ACE wrap) to provide gentle, uniform pressure and support the distended joint capsule.
   • Elevation: Elevate the affected limb above the level of the heart to facilitate venous and lymphatic drainage, decreasing swelling.
3. Physical Therapy & Mobilization Timing:
   • Active Range of Motion (ROM): Initiated ONLY AFTER active bleeding has completely resolved and joint swelling has receded (typically 48 to 72 hours post-infusion) to restore joint function and prevent permanent contractures.
   • PASSIVE RANGE OF MOTION IS STRICTLY CONTRAINDICATED during the acute bleed, as forced manipulation risks re-rupturing fragile clotting vessels and re-initiating hemarthrosis.

Analgesic Safety & Absolute Medication Contraindications

• Safe Analgesics: Acetaminophen (Tylenol) is the first-line mild analgesic. For severe acute pain, oral or parenteral opioids (codeine, oxycodone, morphine) are safe and effective.
• STRICTLY FORBIDDEN DRUGS (ASPIRIN & NSAIDs):
  • Aspirin (acetylsalicylic acid): Irreversibly acetylates platelet cyclooxygenase-1 (COX-1), permanently abolishing platelet thromboxane A2 synthesis for the entire 7- to 10-day lifespan of the platelet. In a patient with an existing secondary clotting factor defect, crippling primary platelet function precipitates catastrophic, uncontrollable hemorrhage!
  • Nonsteroidal Anti-Inflammatory Drugs (NSAIDs - Ibuprofen, Naproxen, Ketorolac): Reversibly inhibit platelet aggregation and cause gastric mucosal erosions, increasing the risk of massive upper gastrointestinal bleeding. Routine NSAIDs are contraindicated unless approved by a comprehensive hemophilia center with concurrent factor coverage.

Clinical Nursing Procedures & Home Safety Counseling

• Minimize unnecessary IM injections: Coordinate procedures with hematology. Vaccines retain their product-specific route; if IM vaccination is judged appropriate, use a fine needle and firm pressure without rubbing for at least 2 minutes under the CDC bleeding-disorder precautions. Do not change all childhood immunizations to the subcutaneous route.
• Avoid Rectal Procedures: Never obtain rectal temperatures or administer rectal suppositories/enemas due to the risk of rectal mucosal laceration.
• Venipuncture Safety: Venipunctures are preferred over fingersticks or heelsticks because superficial dermal capillaries bleed continuously; apply firm pressure for 5 minutes post-phlebotomy.
• Dental Care: Soft-bristled toothbrush, regular dental examinations, water flossers.
• Sports & Activity Guidance: Encourage non-contact physical activities that promote cardiovascular fitness and strengthen musculature around joints (e.g., swimming, walking, golf, badminton, bicycling with safety helmet and protective joint pads). COLLISION AND CONTACT SPORTS ARE STRICTLY PROHIBITED (e.g., football, wrestling, rugby, lacrosse, ice hockey, boxing).
• MedicAlert: The child must wear a medical identification bracelet stating their specific hemophilia type, severity, and factor regimen at all times.

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5. Immune Thrombocytopenia (ITP): Etiology & Pathophysiology

Immune Thrombocytopenia (formerly termed Idiopathic Thrombocytopenic Purpura) is the most common cause of acute thrombocytopenia in previously healthy children, exhibiting an annual incidence of 3 to 8 cases per 100,000 children.

Autoimmune Pathogenesis

1. Triggering Event: In over 70% to 80% of pediatric cases, ITP is preceded 1 to 4 weeks prior by a common viral illness (upper respiratory tract infection, Epstein-Barr virus, cytomegalovirus, varicella) or live viral immunization (e.g., MMR).
2. Antibody Generation: The child's immune system generates anti-viral antibodies that cross-react with normal self-platelet membrane glycoproteins (molecular mimicry), predominantly glycoprotein IIb/IIIa (GPIIb/IIIa) or GPIb/IX complexes.
3. Splenic Phagocytosis: These circulating autoantibodies (primarily IgG) coat circulating platelets. As antibody-coated platelets transit through the spleen, splenic macrophages express Fc-gamma receptors that bind to the Fc portion of the antiplatelet IgG. The macrophages phagocytose and lyse the platelets within the reticuloendothelial system.
4. Shortened Lifespan: Normal platelet lifespan (7 to 10 days) collapses to a few hours. Although bone marrow megakaryocytes ramp up production, compensatory thrombopoiesis is overwhelmed, driving the peripheral platelet count down precipitously.

Clinical Presentation & Bleeding Classifications

• Epidemiology: Peak age is 2 to 5 years, with equal sex distribution.
• Onset: Sudden, explosive emergence of bleeding manifestations in a thriving, non-toxic child:
  • Cutaneous Bleeding (Dry Purpura): Widespread, non-blanching pinpoint petechiae, purpuric lesions, and extensive ecchymoses occurring spontaneously or following minimal contact ("bruising out of proportion to minor trauma").
  • Mucosal Bleeding (Wet Purpura): Epistaxis (profuse nosebleeds), gingival bleeding with toothbrushing, subconjunctival hemorrhage, and buccal mucosal purpura / hemorrhagic bullae inside the mouth. Wet purpura indicates a significantly higher risk of internal bleeding.
  • Gastrointestinal & Genitourinary: Microscopic hematuria, bloody stools, or heavy menorrhagia in adolescent females.
  • Intracranial Hemorrhage (ICH): The most devastating, life-threatening complication, occurring in < 0.5% to 1% of pediatric patients, almost exclusively in those with platelet counts < 10,000/mcL who sustain head trauma.
• Natural History: In > 80% of children, acute ITP is benign and self-limiting, resolving completely and spontaneously within 6 months. Chronic ITP is defined as persistent thrombocytopenia lasting beyond 12 months (more common in adolescents and females, warranting evaluation for systemic lupus erythematosus).

Diagnostic Hallmarks: The Rule of "Isolated Thrombocytopenia"

• Complete Blood Count (CBC): Reveals isolated, profound thrombocytopenia, frequently with platelet counts < 20,000/mcL (often < 10,000/mcL; normal: 150,000 to 450,000/mcL).
• Normal Hemoglobin, Hematocrit & White Blood Cells: Erythrocyte and leukocyte parameters are completely normal (unless significant blood loss anemia has occurred from severe epistaxis or menorrhagia).
• Peripheral Blood Smear: Confirms true thrombocytopenia and demonstrates large, young platelets (megathrombocytes), indicating vigorous compensatory bone marrow release. Smear must show normal RBC and WBC morphology without blast cells or schistocytes.
• Coagulation Studies: PT/INR, aPTT, and fibrinogen are completely normal.
• Role of Bone Marrow Aspiration: Bone marrow biopsy is NOT routinely indicated in typical pediatric presentations (healthy child, sudden onset, isolated thrombocytopenia, absence of lymphadenopathy or organomegaly). It shows normal or increased megakaryocytes with normal erythroid/myeloid precursors. Indications for marrow aspiration: Unexplained bone/joint pain, unexplained fever, hepatosplenomegaly, lymphadenopathy, concurrent anemia/leukopenia, or failure to respond to standard therapy (to rule out Acute Lymphoblastic Leukemia or aplastic anemia prior to starting corticosteroids).

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6. Pharmacological Protocols & Nursing Care in ITP

The fundamental goal of pediatric ITP management is preventing serious bleeding, not merely normalizing a laboratory number.

Management Stratification

1. Expectant Management ("Watchful Waiting"):
   • Children with mild cutaneous bleeding (petechiae and ecchymoses only; "dry purpura") and no active mucosal bleeding, regardless of platelet count, can be managed safely with outpatient observation and activity counseling without pharmacotherapy.
2. Pharmacological Therapy:
   • Indicated for active mucosal bleeding (epistaxis, GI bleeding; "wet purpura"), platelets < 10,000 to 20,000/mcL with significant bleeding risk, or impending surgery.

First-Line Pharmacological Agents

• Oral Corticosteroids (Prednisone):
  • Dosed at 2 to 4 mg/kg/day orally for 4 to 7 days, followed by a rapid taper. Corticosteroids downregulate Fc-receptor expression on splenic macrophages, decreasing platelet destruction, and promote vascular endothelial stability. Platelet counts typically rise within 48 to 72 hours.
• Intravenous Immune Globulin (IVIG):
  • Dosed at 1 g/kg/day for 1 to 2 consecutive days (or 0.8 to 1 g/kg as a single dose).
  • Mechanism: Infuses high concentrations of monomeric human IgG that competitive-bind and saturate the Fc-receptors on splenic macrophages, physically blocking them from binding and engulfing antibody-coated platelets. Platelet count increases rapidly within 24 to 48 hours in > 80% of patients.
  • Adverse effects: Infusion-related chills, fever, headache, nausea, and aseptic meningitis. Pre-medicate with acetaminophen and diphenhydramine; infuse slowly.
• Anti-D Immune Globulin (WinRho SDF):
  • Dosed at 50 to 75 mcg/kg IV infused over 3 to 5 minutes.
  • Mechanism: Anti-D binds to the Rh(D) antigens on the patient's circulating red blood cells. Splenic macrophages preferentially bind and clear these antibody-coated RBCs, sparing the platelets (competitive immunological decoy).
  • CRITICAL PREREQUISITES FOR USE (EXAM MUST-KNOW):
    1. The patient MUST be Rh(D)-positive.
    2. The patient MUST have an INTACT SPLEEN (completely useless post-splenectomy).
    3. The patient MUST have a negative direct antiglobulin test (DAT / Coombs) and normal baseline hemoglobin.
  • FDA Black Box Warning: Can trigger acute, severe intravascular hemolysis, hemoglobinuria, acute renal failure, and death. Monitor vital signs and urine color for at least 4 hours post-infusion; verify baseline hemoglobin is >= 10 g/dL.

The Transfusion Rule: Why Platelets Are Contraindicated

Nursing Safety Precautions in ITP

• Enforce physical activity restrictions: strictly prohibit contact sports, trampolines, gymnastics, and roughhousing until platelets exceed 50,000/mcL.
• Eliminate all antiplatelet medications (aspirin, NSAIDs, ibuprofen).
• Use a soft-bristled toothbrush or foam toothed swabs; avoid dental flossing.
• Pad crib rails and sharp furniture edges for toddlers.
• Apply direct pressure to minor bleeding or epistaxis for at least 10 to 15 continuous minutes with the child sitting upright and head tilted slightly forward.

Source check

CDC vaccination special situations, checked October 18, 2026. Verify product, age, indication, dose limits, and the applicable institutional order before clinical administration.