A sacral dimple is a pit in the midline of skin overlying the spine, often detected in the newborn or early infant period.
Sacral dimples are diagnosed by simple clinical examination. Simple, single sacral dimples do not require any further imaging. Those with the following clinical characteristics should be considered higher risk for the possibility of an underlying neural tube defect:
- size: greater than 0.5 cm width across the base
- depth: cannot adequately visualise the base even with spreading of the lateral skin
- position: those higher than the gluteal folds
- associated cutaneous features: hypertrichosis (dark hairs) from the base, distinct colour change within the base
- Sacral dimples which have a clearly visualised base with a width of < 0.5 cm, are positioned below the gluteal folds and have no other cutaneous features (dark hair, colour change) are innocent and do not require any further investigation.
- Sacral dimples with higher risk characteristics should undergo ultrasound.
Investigations are often not required for sacral dimples. Sacral dimples which have a clearly visualised base with a width of < 0.5 cm, are positioned below the gluteal folds and have no other cutaneous features (dark hair, colour change) are innocent and do not require any further investigation.
Ultrasound is the first line investigation for those with higher risk features.
MRI spine can be considered if the ultrasound shows features suggestive of spina bifida occulta or other neural tube defects, although can be organised after specialist input.
- Paediatrician
- Referral to paediatric outpatient services is not required for simple single sacral dimples, and is only required for higher risk dimples with abnormal or inconclusive ultrasound, or abnormal neurological signs.