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Skin signs of non-accidental injury

Author: Matthew Scorer, Medical Student, Peninsula Medical School, Exeter, United Kingdom (elective, Auckland, New Zealand 2010).



Physical abuse (non-accidental injury) can be a difficult diagnosis for physicians to consider, both emotionally and clinically. Injuries in the skin can be an important sign of physical abuse. Skin signs of non-accidental injury are frequently accompanied by other forms of physical injury (e.g. fractures, brain damage, internal injuries) and other forms of abuse such as emotional abuse and neglect.

Child abuse is the most frequently discussed area, but adults can also be abused.

A combination of physical symptoms and signs, past medical history, behavioural patterns, and the psycho-social situation of a patient may raise the suspicion of abuse.

What is non-accidental injury?

Non-accidental injury or physical abuse is any bodily injury that is deliberately inflicted on a vulnerable person that is considered unacceptable in a given culture at a given time. This may include hitting, kicking, burning, biting or choking.

What other categories of abuse exist?

The wider term “abuse” refers to any treatment of a child or vulnerable adult that is considered unacceptable in a given culture at a given time. It is commonly categorised into four types:

  1. Physical abuse (or non-accidental injury): bodily injury is deliberately inflicted, or the victim is forced to engage in harmful activity.
  2. Sexual abuse: forced or inappropriate engagement in sexual acts or exposure to sexual materials.
  3. Emotional abuse: demeaning or distant behaviour that may cause the failure of normal psychological or social development.
  4. Neglect: the basic needs of life such as food, clothing and shelter are not provided by the carer or guardian.

What are the signs and symptoms of non-accidental injury?

The most common lesions caused by non-accidental injury are bruises and abrasions, followed by lacerations, scratches, soft tissue swellings, strap marks, haematomas, thermal burns and bites. In addition, the history of the presentation may raise the suspicion of non-accidental injury, for example:

  • Delay in seeking medical attention.
  • The details of the mechanism of injury are implausible, change over time, or are inconsistent with the developmental stage of the child.
  • Lack of concern by the person accompanying the child.
  • Abnormal behaviour or demeanour by the child e.g. withdrawn, avoiding eye contact. This should be observed in the context of the child's background – for example it is usual to avoid eye contact in some Pacific cultures.
  • Direct disclosure by the child that the injury was deliberately inflicted.


Physical abuse is frequently identified by bruising, which may be multiple and in different stages of healing. The location of the bruised area may be suspicious. Whereas bruising from accidental trauma is usually over bony prominences (e.g. knees, elbows, shins, forehead), intentional injury often leads to bruising on the softer regions of the thighs, abdomen, buttocks, cheeks, neck and anogenital regions.

Bruises may have a particular pattern or shape indicative of how they were inflicted. Examples include hand-shaped bruises, the imprint from a belt buckle, linear bruising from being struck by a rod or stick, and curvilinear loop marks caused by striking with a cable or cord.

Other signs of violent physical trauma can accompany bruising. These may include haematomas, traumatic hair loss and traumatic fractures of bone.

Thermal burns

Burning is an especially traumatic form of abuse for children. Typically, cigarette burns can often be suspected where there are one or more rounded ulcers or erosions. There may also be singed vellus hairs.

Branding injuries may be caused by contact with heated metal objects such as spoons or forks and may represent the shape of the object.

Immersion burns of the buttocks and extremities are caused by dunking a child into scalding water. They tend to be sharply demarcated in a “glove and stocking distribution”, with a uniform depth of burn. “Donut-type sparing” may occur on the buttocks where the buttocks are pressed against the bottom of the tub while the surrounding immersed skin is scalded.


Human bites leave an indentifying mark on the victim, so it is particularly important to photographically record them if possible. If the distance between the marks from the canine teeth is greater than 3 cm, the perpetrator possesses adult dentition. Human bites tend to cause a crush injury rather than puncture wounds. Animal bites may be distinguished by the narrower puncture marks and different spacing.

Binding injuries

Binding injuries occur when the wrists and ankles are tied. Acute injuries may present with soft-tissue swelling, redness, warmth or abrasions around the wrists and ankles. Older, healed injuries may present with post-inflammatory pigment change circumferentially around the wrists or ankles.

Signs of neglect

Physical neglect may be present with a combination of poor hygiene, malnutrition, and sometimes untreated illness, which could include dermatitis or infestations of the skin (scabies) and hair (head lice). A neglected child that has not received the usual childhood immunisations may present with infections such as measles.

What diseases can mimic non-accidental injury?

As well as recognising signs suggestive of deliberate harm, physicians should also be aware of the differential diagnosis and conditions that may simulate non-accidental injury.

The appearance of bruising or purpura may be caused by disorders of coagulation, vasculitis, panniculitis, connective tissue disorders such as Ehlers-Danlos syndrome, perniosis or lichen sclerosus. Non-deliberate mechanisms of trauma causing bruising can include play or sports injuries, hair combing, car seat belts, and valsalva petechiae from coughing or vomiting.

Dermal melanocytosis (Mongolian blue spots) have been mistaken for bruises by non-medical personnel such as childcare workers.

Phytophotodermatitis is the sensitisation of skin to sunlight by chemicals found in plants, and has been mistaken for non-accidental injury, particularly when causing bruise-like hyperpigmentation in the shape of hand-prints.

Bullous / blistering diseases can mimic burns or unusual scars.

Folk medicine remedies that can mimic deliberate injury include coin rubbing (cao gio), cupping, moxibustion, and maqua (Arabic therapeutic burns).

What is the management of non-accidental injury?

The child must be examined in a comfortable and supportive environment. It is important to document the history and physical findings in meticulous detail. If possible, photographs should also be taken. Examination of the whole skin and mucosal surfaces should be undertaken. There will usually be a legal obligation to report physical abuse, neglect, or sexual abuse of children. Check with the laws and protocols of your place of work, and obtain legal advice if you are unsure.

Treat any injury or infection as appropriate. Investigations such as a full blood count and clotting screen may be prudent when considering differential diagnoses.



  • Book: Rook’s Textbook of Dermatology. Burns T, Breathnach S, Cox N, Griffiths C. Seventh edition. Blackwell Scientific Publications.
  • Book: Fitzpatrick’s Dermatology in General Medicine. Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI. Sixth edition. McGraw-Hill Medical Publishing.

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