Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Haemophilia and inherited bleeding disorders
Paediatrics and child health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Head injury or critical-site bleed
Any significant head injury, sudden severe headache, neurological change, neck or throat swelling, gastrointestinal haemorrhage, major trauma, iliopsoas bleed or uncontrolled bleeding in a child with an inherited disorder is time-critical.
Action: Use ABCDE, contact the haemophilia centre immediately and give the child's prescribed factor or bypassing treatment before imaging or transfer when a serious bleed is suspected; do not wait for coagulation results, CT or visible swelling.
Overview
Recognise inherited deficiencies of coagulation factors and primary haemostasis, investigate bleeding by phenotype before screening-test shortcuts, treat serious injury before imaging, and coordinate prevention, procedures, family testing and daily participation with a haemophilia centre.
Build a structured bleeding history: neonatal bleeding, circumcision, immunisations, dental work, surgery, trauma, epistaxis duration, oral bleeding, menorrhagia, haemarthrosis, muscle swelling and delayed re-bleeding. Ask what haemostatic challenge actually occurred; a child with no surgery cannot be described as having tolerated it. Record relatives on both sides, consanguinity, diagnosed variants, miscarriages and bleeding in girls as well as boys. Use a validated paediatric bleeding-assessment tool through specialist services where available.
In an emergency, read the treatment card before drawing conclusions from severity labels. Establish usual factor product or non-factor prophylaxis, inhibitor history, last dose, home supply and vascular access. Examine ABCDE, neurological state, mouth and neck, abdomen, muscles, joints and neurovascular status, but avoid repeated palpation of a tense bleed. Normal vital signs or a small external bruise cannot exclude intracranial, retroperitoneal or deep-muscle haemorrhage.
Practice
Two practice questions
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Question 1 of 2
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Paediatrics and child healthOriginal SBA
Head injury sequence
A 9-year-old with severe haemophilia A on factor prophylaxis strikes his head and develops headache and vomiting. What is the most appropriate immediate sequence?
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
For a significant head injury or suspected critical-site bleed, administer prescribed haemostatic treatment immediately and call the comprehensive haemophilia centre. Imaging follows treatment. In standard-half-life haemophilia A without inhibitor, one UK paediatric protocol uses factor VIII 40 to 50 IU/kg for head or major bleeding, targeting 80 to 100 IU/dL; haemophilia B uses factor IX 80 to 100 IU/kg. The individual plan overrides generic calculations because product recovery, half-life, inhibitors and emicizumab change management.
For new diagnostic investigation, order FBC and film, PT, APTT and fibrinogen with careful sample collection. A prolonged APTT that corrects on mixing suggests factor deficiency, but factor assays confirm the specific defect. Von Willebrand factor antigen and activity, factor VIII and blood group context require specialist interpretation and often repeat testing because stress, inflammation, hormones and age alter levels. Normal PT and APTT cannot rule out von Willebrand disease, platelet dysfunction or factor XIII deficiency.
Long-term haemophilia care aims to prevent every important bleed. The centre individualises factor or non-factor prophylaxis from phenotype, pharmacokinetics, venous access, activity and family preference and monitors breakthrough bleeding and inhibitors. Prompt home therapy enables ordinary school and sport with sensible risk planning. A suspected haemarthrosis needs early treatment, analgesia that does not impair platelets, relative rest initially and haemophilia physiotherapy to restore safe movement and prevent recurrent target-joint damage.
Procedures are planned, never improvised. The dentist, surgeon, anaesthetist and haemophilia team agree factor or desmopressin suitability, antifibrinolytic cover, laboratory targets and post-procedure monitoring before an injection, extraction or operation. Desmopressin is only useful in responsive mild haemophilia A or selected von Willebrand disease after a documented test response; fluid restriction and sodium monitoring prevent hyponatraemia, and it is not used for haemophilia B.
Management includes family testing, genetic counselling, vaccination using an agreed route, safe analgesia, school emergency plans, physiotherapy, dental prevention and transition skills. Encourage appropriate physical activity to build strength and bone health. A mature child should learn their product, emergency dose and centre contacts progressively. Consider iron studies for recurrent mucosal or menstrual bleeding and include menstrual management, sexual health and pregnancy implications in adolescent care.
Key points
Haemophilia causes deep muscle, joint and post-procedural bleeding; von Willebrand and platelet disorders more often cause epistaxis, gum bleeding, menorrhagia and easy bruising.
Treat suspected serious bleeding first: factor or the child's prescribed alternative should precede CT, transfer, suturing or other diagnostic delay.
Use the child's emergency card and individual plan, contact the haemophilia centre and identify product, dose, inhibitor status, venous access and recent treatment.
First-line investigation of unexplained bleeding is phenotype-led history, examination, FBC and film, PT, APTT and fibrinogen, but normal screening tests do not exclude von Willebrand disease, platelet dysfunction or factor XIII deficiency.
Reference-standard confirmation uses specific factor activity, von Willebrand antigen and activity, platelet studies and molecular testing selected by a specialist laboratory.
An isolated prolonged APTT can fit factor VIII, IX or XI deficiency; a normal APTT does not exclude mild haemophilia, and sample handling or age affects results.
Severe haemophilia needs prophylaxis individualised by the comprehensive care centre; adherence, trough protection, activity and breakthrough bleeds guide adjustment.
Avoid aspirin and usually NSAIDs, intramuscular injections, blind arterial puncture and invasive procedures without haemostatic planning.
Aetiology
01
Haemophilia A and B
Pathogenic F8 or F9 variants reduce factor VIII or IX; inheritance is usually X-linked, but new variants and clinically affected girls or women occur.
02
Von Willebrand disease
Quantitative or qualitative von Willebrand factor abnormalities impair platelet adhesion and may reduce factor VIII stability, commonly causing mucocutaneous bleeding.
03
Rare factor deficiencies
Autosomal-recessive deficiencies including factors XI, XIII, VII and fibrinogen disorders have distinct phenotypes and screening-test patterns.
04
Inherited platelet disorders
Defects of platelet receptors, granules or signalling cause mucosal and procedural bleeding despite a sometimes normal platelet count.
Pathophysiology
1
Secondary haemostasis failure
Factor VIII or IX deficiency limits thrombin generation and fibrin reinforcement, so an initial plug forms but fails to secure deep tissue haemostasis.
2
Deep-tissue bleeding
Muscle and joint bleeding can continue after trauma or spontaneously, causing pressure, pain, inflammation and progressive tissue damage.
3
Primary haemostasis failure
Von Willebrand or platelet disorders impair adhesion and plug formation, producing epistaxis, gum bleeding, menorrhagia and immediate procedural bleeding.
4
Inhibitor development
Neutralising antibodies can develop against replacement factor, making usual doses ineffective and requiring specialist bypassing or immune-tolerance strategies.
5
Recurrent synovial injury
Blood within a joint drives synovitis, cartilage damage, muscle inhibition and a cycle of repeated haemarthrosis leading to chronic arthropathy.
Clinical features and red flags
Haemarthrosis
Early tingling, warmth, pain and reduced movement progress to swelling and flexed posture, often before bruising appears.
Deep-muscle bleed
Pain, swelling, reduced function and neurological or vascular compression can conceal a substantial blood loss.
Mucocutaneous phenotype
Recurrent epistaxis, gum bleeding, easy bruising and heavy periods point toward von Willebrand or platelet dysfunction.
Delayed re-bleeding
Bleeding that restarts after apparently normal initial haemostasis can occur in factor XIII and fibrin-stabilisation disorders.
Inhibitor clue
A known haemophilia bleed that fails to respond as expected to the correct factor dose suggests a neutralising antibody.
Red flags requiring action
Head injury, severe headache, vomiting, drowsiness, seizure or focal neurological deficit requires immediate haemostatic treatment and urgent neuroassessment.
Neck, tongue or retropharyngeal bleeding can obstruct the airway before external swelling becomes dramatic.
Hip flexion with groin, abdominal or back pain may represent an iliopsoas bleed with femoral-nerve and major-volume consequences.
Painful tense limb swelling, paraesthesia, weakness or reduced pulses suggests compartment syndrome and needs factor treatment plus urgent surgical review.
Investigations
01First-line FBC and peripheral filmFirst stepFirst line
Why
Assess platelet number, anaemia from blood loss and abnormal platelet morphology.
Interpretation and limitations
A normal platelet count fits factor deficiency; thrombocytopenia or giant platelets redirects the inherited bleeding differential.
02First-line PT, APTT and fibrinogenFirst line
Why
Screen extrinsic, intrinsic and common pathways and identify broad acquired coagulopathy.
Interpretation and limitations
Isolated prolonged APTT suggests VIII, IX or XI deficiency or an inhibitor; normal tests do not exclude several important disorders.
03Mixing study
Why
Differentiate a factor deficiency pattern from an inhibitor in unexplained prolonged APTT.
Interpretation and limitations
Correction after mixing supports deficiency; non-correction suggests an inhibitor, though time-dependent effects require laboratory expertise.
04Reference-standard specific factor activities
Why
Confirm factor VIII, IX, XI, XIII or other deficiency and quantify clinical severity.
Interpretation and limitations
Interpret age, assay method, acute-phase response and treatment exposure; one-stage and chromogenic assays may differ with some therapies.
Differential diagnosis
01
Immune thrombocytopenia
Petechiae and mucosal bleeding with isolated thrombocytopenia contrasts with the normal platelet count and deep bleeding typical of haemophilia.
02
Non-accidental injury
Bleeding disease does not exclude inflicted harm; injury pattern, explanation, development and safeguarding context must be assessed alongside haemostatic testing.
03
Liver disease or vitamin K deficiency
Multiple acquired factor reductions, systemic illness and broader PT or APTT abnormalities suggest impaired synthesis rather than an isolated inherited defect.
04
Connective-tissue fragility
Joint hypermobility, skin features and easy bruising can reflect vessel or collagen fragility with normal haemostatic investigations.
05
Acquired inhibitor
New severe bleeding without a congenital history and an APTT that fails to correct on mixing raises an acquired factor inhibitor.
Management
01Head or critical-site injuryTreat before imagingFirst stepA child with known or suspected inherited bleeding disease has significant head trauma or a critical-site symptom.+
1Use the emergency card, call the haemophilia centre and give the prescribed factor or bypassing treatment immediately.
2Stabilise ABCDE and arrange urgent imaging, observation and surgical or critical-care review after haemostatic cover.
3Monitor factor recovery or treatment effect and repeat dosing according to the individual specialist plan.
02Suspected joint or muscle bleedStop bleeding and preserve functionNew warmth, pain, restricted movement or swelling is compatible with haemarthrosis or muscle haemorrhage.+
1Give early haemostatic treatment and suitable non-NSAID analgesia.
2Assess neurovascular status and image only when diagnosis, location or complication requires it.
Complications
01
Haemophilic arthropathy
Repeated haemarthroses cause chronic pain, reduced range, deformity and impaired school, sport and later employment participation.
02
Intracranial haemorrhage
Bleeding may follow minor trauma or occur spontaneously and can progress before neurological signs become obvious.
03
Factor inhibitors
Antibodies prevent expected recovery or bleed control, complicating prophylaxis, surgery and emergencies and requiring a comprehensive centre.
04
Treatment-related thrombosis or toxicity
Bypassing agents, non-factor therapies and antifibrinolytics have context-specific thrombotic, renal or electrolyte risks that specialist plans address.
05
Iron deficiency and quality-of-life loss
Repeated mucosal or menstrual blood loss, activity avoidance and treatment burden can affect growth, schooling, mental health and family independence.
Monitoring and follow-up
Document bleed site, onset, treatment time, product, dose, batch and clinical response in the haemophilia record.
Check factor levels before and after treatment for severe bleeding or surgery as directed, without delaying the first emergency dose.
Monitor pain, swelling, range, neurovascular status and haemoglobin in muscle or joint bleeding.
Screen for inhibitors at specialist intervals and whenever expected factor recovery or bleed control is inadequate.
Track annualised bleed rate, target joints, adherence, physical activity and prophylaxis coverage through the comprehensive centre.
With desmopressin repetition, record intake, output, weight and serum sodium under the fluid-restriction plan.
Review dental health, vaccination, growth, bone health, menstruation, iron status, school plans and transition competence longitudinally.
Special situations
Factor precedes the scanner
A normal neurological examination early after head injury does not justify delaying haemostatic treatment.
Screening tests have blind spots
Von Willebrand, platelet and factor XIII disorders may bleed despite normal PT and APTT.
Girls can have clinically important haemophilia
Carrier terminology must not replace factor measurement and phenotype assessment when bleeding is present.
Pain can precede swelling
Treat a familiar joint aura early rather than waiting for visible haemarthrosis.
The individual plan is a prescription
Product, inhibitor and non-factor therapy make generic emergency tables unsafe when a current card is available.
Common pitfalls
01
Sending a child with haemophilia for CT before giving emergency factor.
02
Ruling out inherited bleeding because PT and APTT are normal.
03
Using aspirin, ibuprofen or an intramuscular injection without specialist agreement.
04
Assuming only boys can have clinically significant factor VIII or IX deficiency.
05
Applying a standard factor dose without checking inhibitor or emicizumab status.
06
Immobilising a joint for too long and omitting haemophilia physiotherapy.
07
Performing dental or surgical work without a written haemostatic plan.
08
Allowing a known disorder to end safeguarding assessment prematurely.
Early factor followed by rest, safe ice, compression where appropriate and physiotherapy protects a bleeding joint; prolonged immobilisation worsens recovery.
Assess girls and women explicitly: heavy menstrual bleeding and iron deficiency can be the main manifestation of von Willebrand disease or low factor levels.
A neonate with intracranial, umbilical or post-procedural bleeding, or a child with delayed re-bleeding despite normal PT and APTT, may have factor XIII or another rare deficiency.
A girl with heavy periods, iron deficiency or procedural bleeding and a relevant family history may be a symptomatic haemophilia carrier or have von Willebrand disease.
05Von Willebrand factor panel
Why
Measure antigen, platelet-dependent activity and factor VIII when mucocutaneous bleeding suggests von Willebrand disease.
Interpretation and limitations
Levels vary with stress, blood group, hormones and inflammation, so repeat baseline testing and subtype assays may be required.
06Genetic and specialised platelet testing
Why
Define inheritance, carrier status or platelet-function disease when results change care or counselling.
Interpretation and limitations
Molecular findings require phenotype correlation; a negative panel does not exclude every inherited bleeding disorder.
3
Use relative rest and specialist physiotherapy, then restore movement gradually once haemostasis is secure.
4Review prophylaxis if the same joint bleeds repeatedly.
03New bleeding phenotypeInvestigate in layersRecurrent, disproportionate or procedural bleeding has no established diagnosis.+
1Take a three-generation and challenge-specific history and assess safeguarding context.
2Obtain FBC, film, PT, APTT and fibrinogen with a correctly filled sample.
3Refer for factor, von Willebrand, platelet and genetic testing guided by phenotype and screen results.
4Do not close the case solely because PT and APTT are normal.
04Planned procedureCreate a haemostatic procedure planDental work, surgery, lumbar puncture or another invasive procedure is proposed.+
1Contact the haemophilia centre before scheduling and define product, dose, target and timing.
2Agree antifibrinolytic or desmopressin use only when appropriate to diagnosis and response.
3Plan post-procedure observation, repeat treatment, analgesia and access to urgent review.
Key medicines and prescribing safety3 treatments · regimens, roles and cautions+
Replaces deficient factor rapidly to secure haemostasis before imaging, transfer or emergency intervention.
Factor VIII concentrate for major bleeding
For a child with haemophilia A using a standard-half-life product and no inhibitor, one UK paediatric protocol gives 40 to 50 IU/kg IV immediately for head injury or major bleeding, then repeats 40 to 50 IU/kg every 8 to 24 hours as directed by factor levels and the haemophilia centre.
The individual product and emergency plan override generic dosing; monitor recovery and inhibitor status, use the specialist target, and recognise that emicizumab or a factor inhibitor changes laboratory interpretation and treatment choice.
Restores factor IX activity in major bleeding and provides cover for urgent procedures in haemophilia B.
Factor IX concentrate for major bleeding
For a child with haemophilia B using the allocated product and no inhibitor, one UK paediatric protocol gives 80 to 100 IU/kg IV immediately for head injury or major bleeding and repeats at least every 24 hours until controlled under specialist monitoring.
Product half-life and recovery vary, particularly in young children; use measured levels and haemophilia-centre advice, and do not use desmopressin because it does not correct factor IX deficiency.
Releases endogenous von Willebrand factor and factor VIII for selected minor bleeds or procedures without factor concentrate.
Desmopressin for documented responders
Give 0.3 micrograms/kg, maximum 20 micrograms per dose, IV over 45 to 60 minutes or subcutaneously only for a child with a documented response in mild haemophilia A or selected von Willebrand disease and under the centre plan.
Restrict fluid and monitor sodium and fluid balance with repeated doses because hyponatraemia and seizures can occur; avoid in very young children or cardiovascular instability according to protocol, and never assume response without prior testing.