Sacral dimples (Paediatric Guidelines)

TAM (Treatments and Medicines) NHS Highland
NHS Highland

Audience

  • All NHS Highland
  • Primary care only
  • Paediatrics only

A sacral dimple is an indentation in the lower back, present at birth, but sometimes not noticed until the infant’s 6 week check. Most are blind ending, just above or within the crease of the buttocks, and do not require investigation or treatment.

However, if referral is required for further investigations, please refer as soon as possible. Ultrasound is the initial investigation of choice, but after around 8 weeks of age (after ossification of the vertebral arches) often a MRI needs to be performed.

Referral

Who to refer

Refer if:

  • The dimple is more than 2.5cm above the anal margin
  • The dimple is greater than 5mm in size
  • There are associated cutaneous marking, hairy patch, skin tag, or fatty lump
  • There are associated anorectal malformations
  • They appear in combination with other lesions

The above may be associated with an underlying neurological problem, for example spinal dysraphism.

Please note: As per updated guidance not being able to see the base of the dimple is NOT (on its own) an indication for referral.

History

Information to Include:

  • Is the child otherwise well, thriving and developing normally?

Examination

Information to include:

  • Is the dimple greater than 5mm in size?
  • How far above the anal margin is the dimple?
  • Are there associated skin changes, hairy patch, skin tag or fatty lump?
  • Are there associated anorectal malformations?
  • Do they appear in combination with other lesions?
  • Can the infant move their legs normally?
  • Are there any problems with urination or stooling?
  • If you are sending in a photograph, please ask the parents to place a tape measure next to the dimple / lesion to the position of the anus, so that the reader can estimate the distance from the anal margin.

Please state the concerning features leading to the referral.

Referral pathway

  • SCI Gateway

Suggestions for management whilst waiting for an outpatient appointment:

  • Nothing specific.
  • Please refer as soon as possible so that an ultrasound may be requested, before 8 weeks of age.

Useful resources for parents whilst waiting for an outpatient appointment

  • Nil specific.

Management in Secondary Care

  • Consultant will receive ultrasound spine result and
    • If normal: baby will be discharged
    • If abnormal: advice of neurosurgeon will be sought

Abbreviations

  • cm: Centimetres
  • MRI: Magnetic Resonance Imaging
  • mm: Millimetres

Editorial Information

Last reviewed: 08/09/2025

Next review date: 09/11/2027

Author(s): Paediatric Department.

Version: 1

Approved By: TAM subgroup of the ADTC

Reviewer name(s): P Van Der Heide.

Document Id: TAM717

Related resources

 

References
Pediatrics in Review 2011;32;109. Holly A Zywicke; Curtis J
West of Scotland Neonatal Guideline. Sacral dimples: advice for referrers. April 2025
The Royal College of Radiologists. iRefer [Website]. Available from: https://www.rcr.ac.uk/our-services/irefer/
Guidelines l iRefer [website]. Available from: https://www.irefer.org.uk/guidelines