A sacral dimple (also termed pilonidal dimple or spinal dimple) is a small depression in the skin, located just above the buttocks. The name comes from the sacrum, the bone at the end of the spine, over which the dimples are found.
Sacral dimples are common, occurring in up to 4% of the population. The majority of these dimples are minor and do not represent any underlying disease; however, the minority may be a sign of disease, notably spina bifida. Even so, this is usually the spina bifida occulta form, which is the least serious kind. Sacral dimples are usually spotted in post-natal checks by a pediatrician, who will check:
- Can the floor of the dimple be seen to be covered with skin? If not, it may be that the neural tube is not completely closed.
- Is there a tuft of hair in the dimple? This may also indicate problems.
- Are there any other problems in the examination of the baby, such as weak lower limbs?
- How close to the buttocks is the dimple? The lower, the better.
Additionally, this can be indicative of a possible kidney problem, which is then checked by an ultrasound.
- Flannigan, edited by Christopher (2011). A practical guide to managing paediatric problems on the postnatal wards. Oxford: Radcliffe Pub. pp. 43, 44. ISBN 9781846195068.