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Definition
A sacral dimple is an indentation, present at birth, in the skin on the lower back. It's usually located just above the crease between the buttocks. Also called pilonidal dimples, most sacral dimples are small and shallow. Sometimes, a sacral dimple may be accompanied by increased hair growth in this area.
Most of the time, sacral dimples are harmless and don't require any treatment. Rarely, a sacral dimple may indicate a serious underlying abnormality of the spine or spinal cord.
To rule out any abnormality, your child's doctor may recommend an imaging test. If an abnormality is discovered, treatment depends on the underlying cause.
Symptoms
A sacral dimple consists of an indentation, or "pit," in the skin on the lower back, just above the crease between the buttocks.
When to see a doctor
Most sacral dimples don't require medical attention. However, call your child's doctor if you notice:
- Fluid draining from the dimple
- Swelling, redness or tenderness around the dimple
These signs and symptoms may indicate the sacral dimple has become infected.
Causes
A sacral dimple is a congenital condition, meaning it's present at birth. There are no known causes.
Complications
Rarely, as your child gets older — especially during adolescence and adulthood — the sacral dimple may become infected and form a cyst (pilonidal cyst). This is usually due to hair, oil secretion and friction in the area. If a cyst occurs, your child's doctor may recommend surgery to drain or remove the cyst.
Preparing for your appointment
In general, your child won't need to see a doctor for a sacral dimple. If you notice any signs or symptoms of infection, such as redness, swelling or fluid drainage in the area, consult your child's doctor.
If you have questions about the sacral dimple, you can also bring these up at your child's routine office visits.
Some questions you might want to ask your child's doctor include:
- What causes a sacral dimple?
- Does my child need any tests to be sure there's no other cause?
- Does the area need any special cleaning or care?
- Will the sacral dimple disappear as my child gets older?
- Is any treatment necessary?
- Is a sacral dimple ever associated with more serious conditions?
Tests and diagnosis
Sacral dimples are present at birth and are evident during an infant's initial physical exam.
In most cases, further testing is unnecessary. However, if the dimple is very large or is accompanied by swelling, discoloration, drainage or tenderness, your infant may undergo imaging tests to rule out a more serious condition. These tests may include:
- Ultrasound. Also called sonography, ultrasound is a noninvasive procedure that uses high-frequency sound waves to produce images of structures of the body.
- Magnetic resonance imaging (MRI). This technique uses a magnetic field and radio waves to create cross-sectional images of the body.
Treatments and drugs
Treatment is unnecessary for a simple sacral dimple.
However, if the sacral dimple is deep (extending well below the surface of the skin) or it becomes infected, these findings may indicate another condition that requires treatment.
Rarely, a sacral dimple indicates a more serious condition, such as spina bifida, a serious birth defect that occurs when the tissue surrounding the developing spinal cord of a fetus doesn't close properly. In these rare instances, treatment depends on the underlying cause and may include surgery to correct or minimize the problem.
Lifestyle and home remedies
Keep sacral dimples clean and free of debris through good hygiene, including regular bathing.
Last Updated: 2010-05-15
