Information
Sacral dimples are usually minor congenital anomalies. They occur in 3-8% of children1.
Rarely, dimples can be associated with Occult Spinal Dysraphism (OSD). OSD describes a broad spectrum of underlying spinal cord abnormalities. Most OSD is picked up antenatally on anomaly scan.
In the new-born, isolated midline sacral dimples and small pits can be safely ignored. Only atypical dimples are associated with a high risk for spinal dysraphism, particularly those that are large (>5 mm), high on the back (>2.5 cm from the anus) or appear in combination with other lesions. Ultrasound is the initial investigation of choice in babies <3m of age.
Who to refer:
The following features of dimples are associated with OSD. The infant should be referred urgently to medical paediatrics if two or more are present:
- Multiple dimples
- >5 mm diameter
- Base of dimple is not visible, despite thorough examination (an otoscope may be helpful)
- Dimple is oriented cephalically (i.e. toward the head), not straight down (i.e. caudal)
- Other dermal abnormalities or masses (see below)
- Distance > 2.5 cm from anus
- Abnormal neurological examination
Other signs of OSD that warrant investigation are listed below. The infant should be referred urgently to medical paediatrics if the combination of a sacral dimple and any one of the following features are present:-
- Skin abnormalities (in the area of the dimple):-
– Hypertrichosis (excessive hair)
– Lipoma or other mass
– Pigmented lesions
– Skin tags or tail-like appendages
– Vascular lesions – haemangioma, telangectasia
– Signs of infection such as skin erythema or induration - Anorectal abnormalities
- Aplasia cutis congenita (congenital absence of skin in any location)
- Orthopaedic:-
– Congenital dislocation of the hip
– Leg length discrepancies
– Pes cavus
– Scoliosis
– Talipes
Who not to refer:
Infants with small (<5mm), isolated midline dimples or small pits that do not meet the criteria listed above.
How to refer:
Refer urgently to medical paediatrics RHCYP (Edinburgh & Midlothian) or St. John’s hospital, Livingston (West Lothian).
Sci-Gateway: RHCYP > General Medicine > LI Basic Sign Referral
Sci-Gateway: SJH > Paediatrics >LI Basic Sign Referral
Please ensure that the referral states the f
If OSD is suspected, the infant should be referred urgently to medical paediatrics. Please attempt to reassure the parents appropriately and try to avoid use of the term ‘spina bifida’ as this may lead to unnecessary anxiety.
- Pediatriceducation.org. Does This Sacral Dimple Need to be Evaluated? URL: http://www.pediatriceducation.org/2009/07/20/does-this-sacral-dimple-need-to-be-evaluated. Updated 20/07/2009. Accessed 23/11/2009
- Robinson AJ, Russell S and Rimmer S. The Value of Ultrasonic Evaluation of the Lumbar Spine in Infants with Specific Reference to Cutaneous Markers of Occult Spinal Dysraphism. Clinical Radiology 2005 60:72-77
- Elton S and Oakes WJ. Dermal Sinus Tracts of the Spine. Neurosurgery Focus 2001. 10(1):1-4
- There are some good pictures of various suspicious and reassuring dimples The JNS-Journal of Neurosurgery3.
