A bruise is dark discolouration of skin caused by blood seeping under the skin after small blood vessels near the surface of the skin have been broken. As the bruise heals, the body breaks this blood down and reabsorbs it, turning the mark a typical greenish-blue.
Bruises are usually caused by the child bumping into hard objects, falling off something or being hit with a blunt object. This is particularly common in younger children who are learning to walk.
In young children, the skin is thinner and the bruise is more obvious.
Most bruises are relatively minor and will get better on their own over a period of about ten days. If the bruise is quite large and swollen, then you can apply ice packs to reduce the swelling which will also relieve the pain. Elevating the area, if the bruise is on a leg or an arm, will also reduce swelling.
A painkiller such as paracetamol can be used if the bruise is in a particularly painful position.
When to see your doctor
If your child's bruise is the result of a serious fall from a tricycle or any other traumatic accident (a jungle gym tumble, for example), call your doctor. He or she may want to examine your child for less obvious injuries. You should also call the doctor if your child:
Banged his or her head and has a bruise behind the ear; it may be a sign of a skull fracture
Has a bruise that doesn't fade in 14 days
Is in pain for more than 24 hours
Has a bruise on a large joint (knee, ankle, elbow, wrist) and is reluctant to use the joint or has difficulty moving an arm or leg
Has a cut or abrasion and shows signs of infection, such as pus, unexplained fever, or increased pain and swelling
If your child gets a bruise as a result of an injury to the lower back, check his or her urine for obvious blood. This could indicate injury to the kidneys or other organs. If blood is present, call the doctor immediately.
Finally, unexplained black-and-blue spots may indicate that your child has a tendency to bleed easily. If your child develops bruises that aren't associated with injuries, make an appointment to see your doctor.
A black eye is usually simply a bruise which affects the tissues around the eye. But there are times when this can be a sign of a more serious injury and you should see a doctor if your child:
complains of not being able to see properly or of double vision
cannot move the eye normally in all directions
has pain in the eyeball rather than the eye socket
is bleeding into the white of the eye
If you don't notice any of these symptoms, treat the black eye like any bruise. If it's accompanied by swelling and your child can stand it, apply ice packs for 15-minute periods several times a day during the first 48 hours to reduce swelling. If you don't have an ice pack handy, you can make one by filling a zip-lock bag with ice cubes and water, or partially thawing a package of frozen peas or corn. If the bruise seems painful, call your doctor and ask whether it's okay to give your child paracetamol. Most black eyes will go away within a week to 10 days. If your child's doesn't within 14 days, consult your doctor.
Reviewed by Prof Don du Toit, University of Stellenbosch