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OverviewAetiologyPathophysiologyClinical features and red flagsInvestigationsDifferential diagnosisManagementComplicationsMonitoring and follow-upSpecial situationsCommon pitfallsQuestionsSources
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Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.

Bruising and injury in non-mobile children

Paediatrics and child health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

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Unwell infant with a sentinel injury

A non-mobile infant with altered consciousness, seizures, apnoea, vomiting, poor feeding, pallor, abdominal signs or physiological instability may have occult head or visceral trauma.

Action: Start ABCDE and urgent senior paediatric care, obtain time-critical imaging and treatment according to findings, and activate child-protection procedures concurrently. Ensure continuous safe supervision, preserve relevant clothing or samples, and contact children's social care and police when immediate protection or suspected crime requires joint action.

Overview

Treat bruising or injury in a non-mobile child as a sentinel clinical finding, identify emergencies and mimics, arrange an urgent complete assessment, investigate occult harm and establish a safe multi-agency plan.

A non-mobile child is one who is not yet able to move independently through crawling, bottom shuffling, cruising or walking. Age is an imperfect substitute for actual function, so record achieved milestones. Bruising in this group is uncommon and can be the earliest visible marker of inflicted harm. It should therefore trigger an urgent, structured assessment rather than automatic attribution to ordinary handling.

First determine whether the infant is clinically well. Ask about feeding, vomiting, apnoea, seizures, altered alertness, irritability and limb use. Perform ABCDE and careful neurological observation. A small surface lesion does not predict the amount of underlying injury, and significant head or abdominal trauma may have few external signs. Urgent treatment and safeguarding are parallel responsibilities.

Build a precise chronology. Record when the skin was last seen normal, who first found the lesion, all caregivers, recent healthcare procedures, birth history, medicines, bleeding symptoms and family history. Clarify the proposed contact surface and infant position without suggesting an answer. Separate each person's account and retain exact terms used for actions and timings.

Practice

Two practice questions

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Paediatrics and child healthOriginal SBA

Sentinel injury response

A clinically stable 3-month-old who cannot roll has a new 1 cm cheek bruise. There is no clear explanation. Which next step best reflects safe UK practice?

Choose one answer, then submit
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Sources and review status3 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NICE CG89 When to suspect child maltreatmentRecommendations address bruising, fractures, intracranial injury and other alerts requiring consideration or suspicion of maltreatment.
  • NICE NG76 Child abuse and neglectThe national pathway supports careful assessment, communication and timely response to possible abuse in babies and children.
  • RCPCH Child Protection EvidenceSystematic evidence reviews support specialist interpretation of bruising, fractures, head injury and related child-protection presentations.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom

The physical examination takes place in good light with privacy, warmth and a chaperone. Fully undress the infant, assess growth and development, and inspect scalp, ears, eyes, mouth, frenula, neck, torso, genital area, buttocks, limbs, palms and soles. Describe size, shape, colour, border, swelling and tenderness. Follow local standards for body maps and secure clinical photography.

Investigations are selected with a senior child-protection paediatrician. Haematology testing addresses plausible bleeding disorders but no universal panel interprets every child. A specialist skeletal survey can detect occult fractures and commonly includes planned follow-up views. Neuroimaging and ophthalmology are considered from age, symptoms and concern, while liver or pancreatic markers may prompt abdominal imaging. Every result must have an identified reviewer.

The decision to refer does not require proof of who caused the injury. Share the developmental discrepancy, lesion description, history and clinical differential with children's social care and safeguarding professionals. Police may need early involvement for immediate safety or evidence preservation. Discharge is inappropriate until a documented plan names the safe caregiver, location, supervision, transport, outstanding work and contingency if arrangements change.

Key points

  • Bruising is unusual in a child who cannot move independently; arrange urgent same-day paediatric safeguarding assessment.
  • Stabilise neurological, respiratory or circulatory compromise immediately and consider covert head, skeletal and abdominal injury.
  • Establish the infant's achieved milestones and reconstruct who noticed the mark, when, where and after what exact event.
  • Undress and examine the whole infant respectfully, including mouth and scalp, while measuring and describing every lesion.
  • Do not use bruise colour to estimate age, and do not assume one medical mimic explains all findings.
  • Use senior-guided laboratory and imaging protocols, which may include skeletal survey, neuroimaging and targeted abdominal assessment.
  • Review previous attendances and consider siblings, twin or other young children exposed to the same caregiving environment.
  • Refer concerns promptly, document a named safe plan and assign ownership for follow-up imaging and pending results.

Aetiology

01

Inflicted impact or grip

Blows, pinching, forceful gripping or impact can injure compliant infant tissues and may leave small bruises that precede more severe assault.

02

Accidental contact

Medical procedures, birth trauma, straps or genuine accidents can mark skin, but the account must match exact location, timing and developmental opportunity.

03

Medical susceptibility

Coagulation disorders, thrombocytopenia, vascular lesions, infection and connective-tissue disease can cause or amplify bruising and require targeted clinical evaluation.

Pathophysiology

  1. 1
    Capillary disruption

    Mechanical force allows blood to enter soft tissue; lesion visibility depends on depth, tissue perfusion and pigmentation rather than a predictable colour timetable.

  2. 2
    Limited self-generation

    Before crawling, cruising or walking, infants have few opportunities to acquire ordinary impact bruises; rolling alone often remains within local non-independently-mobile infant pathways.

  3. 3
    Sentinel escalation

    A small overlooked injury may reflect an earlier episode in a pattern that later progresses to fracture, visceral damage or abusive head trauma.

Clinical features and red flags

Sentinel bruise

A small bruise in a pre-mobile infant may be the only visible sign before later serious inflicted injury.

Oral sentinel injury

Unexplained lip, tongue, palate or frenulum trauma can result from force and deserves the same whole-child assessment.

Patterned contact

Parallel lines, loops, fingertip clusters or a recognisable object shape suggest focused external force rather than diffuse accidental contact.

Neurological accompaniment

Reduced feeding, vomiting, seizures, apnoea or altered interaction alongside minor bruising raises concern for concealed head injury.

Red flags requiring action

  • Any unexplained bruise in a child who is not yet independently mobile warrants urgent professional assessment rather than routine watchful waiting.
  • Bruises on ears, neck, cheeks, torso, buttocks or genital region, patterned marks, clusters or petechiae around an injury require careful explanation.
  • Oral bleeding, torn frenulum, scalp swelling or subconjunctival haemorrhage may be sentinel injuries even when the infant appears comfortable.
  • A history of a short fall cannot simply be accepted as explaining severe neurological, skeletal or internal injury without specialist correlation.

Investigations

  1. 01
    Full clinical and developmental assessmentFirst step
    Why
    Confirm mobility, characterise lesions and detect additional injury or illness.
    Interpretation and limitations
    Risk is judged against achieved function and the complete examination, not an age threshold or isolated photograph.
  2. 02
    Coagulation and blood evaluation
    Why
    Identify anaemia, thrombocytopenia or a plausible haemostatic disorder.
    Interpretation and limitations
    Testing is guided by history and specialist protocols; abnormalities require haematology interpretation and may coexist with trauma.
  3. 03
    Specialist skeletal imaging
    Why
    Look for occult fractures when maltreatment is suspected in a young child.
    Interpretation and limitations
    Technique and reporting require paediatric radiology expertise, with follow-up views arranged at the protocol-defined interval.
  4. 04
    Neuroimaging assessment
    Why
    Detect intracranial and related injury in symptomatic or high-risk infants.
    Interpretation and limitations
    Urgent CT evaluates acute instability; later MRI can define brain and spinal abnormalities under a specialist plan.
  5. 05
    Abdominal injury screen
    Why
    Identify occult liver, pancreatic, bowel or renal trauma when indicated.

Differential diagnosis

01

Congenital dermal melanocytosis

Stable blue-grey pigmentation, often over the sacrum or buttocks, can resemble bruising; distribution, persistence and prior documentation clarify the finding.

02

Vascular or inflammatory lesion

Haemangioma, vasculitis, infection and other dermatological disorders may create red or purple marks with a different history and morphology.

03

Haemostatic disorder

Platelet, clotting-factor and systemic disorders may cause unusual bleeding, yet an abnormal result does not automatically account for every injury.

04

Iatrogenic mark

Venepuncture, monitoring, adhesive, resuscitation and handling can produce lesions; precise procedural records should correlate with their anatomical location.

Additional chapter-specific clues

Medical mimic features

Widespread petechiae, mucosal bleeding, stable pigmented lesions or systemic illness redirect testing but do not end safeguarding reasoning.

Management

01TriageFind instability and hidden traumaFirst stepA non-mobile infant presents with bruising, oral trauma or unexplained injury.+
  1. 1Perform ABCDE and assess neurological state, feeding and pain.
  2. 2EscalationEscalate immediately for seizures, apnoea, shock or reduced consciousness.
  3. 3Secure safe continuous supervision while assessment is organised.
  4. 4Start contemporaneous notes before details and timings are lost.
02Whole-child work-upExamine beyond the visible bruiseThe infant is stable enough for structured safeguarding assessment.+
  1. 1Document actual mobility and take separate open caregiver accounts.
  2. 2Undress and inspect every skin surface, mouth and scalp.

Complications

01

Missed occult injury

Focusing on one bruise can miss intracranial haemorrhage, fracture, oral trauma or internal injury requiring urgent treatment.

02

Further severe assault

Sentinel injuries may precede escalating maltreatment, making a delayed or incomplete response potentially life-threatening for the infant or siblings.

03

Unnecessary separation

Overconfident interpretation without differential assessment can cause avoidable family disruption, emphasising disciplined evidence collection and multidisciplinary decision-making.

Monitoring and follow-up

  • Observe consciousness, pupils, breathing, feeding and vital signs when occult head injury remains possible, escalating any change immediately.
  • Re-examine and document lesion evolution clinically without claiming that colour change provides reliable injury dating.
  • Track follow-up skeletal imaging, specialist reports and laboratory interpretation using a named results owner.
  • Communicate new or revised findings to the multi-agency team because they may alter protection arrangements.
  • Confirm attendance at medical follow-up and respond actively to nonattendance rather than closing the safeguarding episode administratively.
  • Review developmental, emotional and caregiver support needs after immediate protection and treatment decisions are settled.

Special situations

Function outranks birthday

An infant's observed and reported mobility determines accidental opportunity more accurately than using chronological age alone.

Small does not mean trivial

Minor bruising or oral injury can precede major assault and therefore carries significance beyond immediate tissue damage.

Photography has governance

Clinical images need secure approved equipment, identifiers, consent considerations and controlled storage; personal phones are inappropriate.

Normal tests are bounded

Each investigation answers a particular question, so normal coagulation or imaging cannot erase concern arising from incompatible history.

The sibling question matters

Twins and other young children may share exposure and need explicit consideration in the referral and safety response.

Common pitfalls

  1. 01

    Treating rolling alone as equivalent to independent mobility instead of recording actual function and applying the local non-mobile-infant pathway.

  2. 02

    Accepting routine handling as an adequate explanation without locating the exact force and contact surface.

  3. 03

    Testing for a bleeding disorder but omitting assessment for occult skeletal or head injury.

  4. 04

    Describing a mark vaguely instead of measuring its dimensions and recording its precise anatomical site.

  5. 05

    Allowing the child to leave while referral ownership or safe supervision remains ambiguous.

  6. 06

    Forgetting planned follow-up imaging because the first skeletal survey has already been reported.

Delay in presentation, changing accounts, prior unexplained injuries or a sibling with suspicious harm increases the need for a coordinated chronology.
  • Sleepiness, irritability, apnoea, seizures, bulging fontanelle, vomiting or abnormal tone can indicate abusive head trauma and needs emergency assessment.
    • Interpretation and limitations
    Clinical signs and biochemical abnormalities guide imaging, while normal skin does not exclude visceral injury.
    3
    Arrange laboratory, skeletal, head and abdominal investigations proportionately.
  • 4Review earlier records and identify other potentially vulnerable children.
    • 03ProtectionRefer before dispositionBruising remains unexplained, incompatible or otherwise concerning after initial review.+
    1. 1Consult senior paediatrics and the safeguarding team without delay.
    2. 2Refer specific facts and uncertainty to children's social care.
    3. 3Coordinate police input when immediate risk or forensic needs exist.
    4. 4Agree the safe destination and ownership of every pending result.