Sacral dimple

Overview

A sacral dimple is an indentation or pit in the skin on the lower back that is present at birth in some babies. It's usually just above the crease between the buttocks. Most sacral dimples are harmless and don't need treatment.

A sacral dimple can be a sign of a serious spinal problem in a newborn if the dimple is large or appears near a tuft of hair, skin tag, lump or discolored area. In these instances, your child's health care provider may recommend an imaging test. If a spinal problem is found, treatment depends on the underlying cause.

Symptoms

A sacral dimple is an indentation or pit in the skin on the lower back. It's usually located just above the crease between the buttocks.

Causes

There are no known causes for a sacral dimple. It is a congenital condition, meaning it's present at birth.

Risk factors

Risk factors for sacral dimples include being born with a spinal cord problem, such as tethered cord syndrome. In this condition the spinal cord doesn't hang free within the spinal canal. Sacral dimples also can be present in newborns without other health conditions.

Complications

Rarely, sacral dimples are associated with a serious underlying abnormality of the spine or spinal cord. Examples include:

• Spina bifida. A very mild form of this condition, called spina bifida occulta, occurs when the spine doesn't close properly around the spinal cord, but the cord remains within the spinal canal. In most cases, spina bifida occulta causes no symptoms and doesn't need treatment.
• Tethered cord syndrome. A spinal cord typically hangs freely within the spinal canal. Tethered cord syndrome is a disorder that occurs when tissue attached to the spinal cord limits its movements. Signs and symptoms may include weakness or numbness in the legs and bladder or bowel incontinence.

The risks of these spinal problems increase if the sacral dimple is accompanied by a nearby tuft of hair, skin tag or lump, and certain types of skin discoloration.