Bruises are due to the leakage of blood into the skin tissue that is produced by tissue damage from a direct blow or a crushing injury. Bruising is the earliest and most visible sign of child abuse. Early identification of bruises resulting from child abuse can allow for intervention and prevent further abuse.

Bruises seen in infants, especially on the face and buttocks, are more suspicious and should be considered nonaccidental until proven otherwise. Injuries to children's upper arms (caused by efforts to defend themselves), the trunk, the front of their thighs, the sides of their faces, their ears and neck, genitalia, stomach, and buttocks are also more likely to be associated with nonaccidental injuries. Injuries to their shins, hips, lower arms, forehead, hands, or the bony prominences (the spine, knees, nose, chin, or elbows) are more likely to signify accidental injury.

Age Dating of Bruises

It is important to determine the ages of bruises to see if their ages are consistent with the caretaker's explanation of the times of injury. Age dating of bruises can often be determined by looking at the color of the bruise. The ages and colors of bruises may therefore show if more than one injury is present. Table 1 shows the ages associated with the colors of bruises.

For example, a 2-year-old boy, not toilet trained, has several yellow-to-brown bruises on his buttocks. The caretaker's explanation for the bruises is that the child tripped in the hallway the day before and fell on his buttocks. This would be suspicious because:

  • Children seldom bruise their buttocks in accidental falls.

  • Bruises on the buttocks are in the primary target zone for nonaccidental injury.

  • The child's diaper (whether disposable or cloth), plastic pants, and clothing would have afforded some protection to his buttocks.

  • If the injuries causing the bruises were sustained the previous day, the bruises should be red to purple.

Another child might have both bright red and brown bruises. The caretaker maintains that all of the bruises were the result of a fall that day. However, the bright red color indicates fresh bruises, while the brown bruises are older. The caretaker's explanation is, therefore, suspicious, and separate explanations must be obtained for each bruise.

Bruise Configurations

Bruises will sometimes have a specific configuration. This may enable law enforcement officers to determine whether bruises are accidental or nonaccidental. One of the easiest ways to identify the weapon used to inflict bruises is to ask the caretaker: How were you punished as a child?

The pattern of a skin lesion may suggest the type of instrument used. Bruise or wound configurations from objects can be divided into two main categories: those from "fixed" objects, which can only strike one of the body's planes at a time, and those from "wraparound" objects, which follow the contours of the body and strike more than one of the body's planes. Hands can make either kind of bruise, depending on the size of the offender's hands and the size of the child. Examples of fixed and wraparound objects include:

  • Fixed objects: coat hangers, handles, paddles.

  • Wraparound objects: belts, closed-end (looped) cords, open-end cords. (Closed-end cords leave a bruise in parallel lines; open-end cords leave a bruise in a single line.)

Natural or Normal Bruising

Injuries inflicted by human hands, feet, or teeth or those inflicted by belts, ropes, electrical cords, knives, switches, gags, or other objects will often leave telltale marks (e.g., gags may leave down-turned lesions at the corners of the mouth). These marks may also help in the investigative process.

For example, the size of bite marks may help to determine the biter's approximate age; their shape may help identify whose teeth made the marks. In some cases, however, bruises are acquired innocently, through play and accidental falls, or when a child has a defect in his or her clotting mechanism. For example, a baby is brought to the hospital with purple bruises on several body surfaces. The parents were unable to provide an explanation other than that the baby "bruised easily." Blood tests later revealed that the baby was a hemophiliac; hemophilia is associated with bruising easily, due to blood clotting problems. There is usually a history of bruising easily in families with such inherited diseases.

Other incidents of "easy bruising" in children can be explained by a low blood platelet count. Multiple bruises can occur in children with leukemia. Diseases causing easy bruising, however, are rare, and inflicted bruises are much more common. The medical diagnosis of clotting disorders requires blood tests and interpretation of those tests by qualified physicians. Therefore, law enforcement officers should try to determine if bruises are the result of an accident or due to physical abuse. Police must also remember never to jump to conclusions and to make a complete investigation of all aspects of suspected child abuse. However, their first duty is to secure the safety of the child quickly.

Mongolian spots (a kind of birthmark) also resemble bruises but can be distinguished by their clear-cut margins, the fact that they do not fade, and their steel gray-blue color. Mongolian spots may be found anywhere on the body (but are typically found on the buttocks and lower back). In addition, they are commonly found in African Americans, Asians, and Hispanics. Investigators should await medical reports when investigating such marks.

The above is provided to help law enforcement personnel determine which injuries and illnesses in children are likely to be the result of abuse. However, it is also very important for law enforcement to work closely with physicians to determine the nature of all injuries.