A dermal sinus tract is a condition present from birth. It consists of a narrow, tube-like channel that extends from the skin’s surface down into the deeper tissues. This tract is the result of incomplete separation of the skin and the nervous system during embryonic development. While some tracts are shallow, others can be more extensive, connecting to the tissues surrounding the spinal cord or the spinal cord itself. The presence of this channel creates a potential pathway from the outside environment into the body.
Physical Signs and Location
The signs of a dermal sinus tract are visible on the skin’s surface, often noticed at birth or during early infancy. These markers can appear as a small pit or dimple in the skin, sometimes with a very small opening. In other instances, a small tuft of hair, a skin tag, or a patch of reddish or discolored skin may mark the location of the tract. These signs are most frequently found along the midline of the body.
The lower back, just above the gluteal cleft, is the most common location. While the lower back is the predominant site, these tracts can form anywhere along the spine’s midline, from the base of the skull down to the tailbone. Less commonly, they can be found on the scalp or near the bridge of the nose.
Diagnostic Imaging and Evaluation
After identifying a potential tract, a physician conducts a physical examination of the skin marker. The goal is to determine the tract’s depth and whether it communicates with the spinal canal. Medical imaging is necessary, as a visual inspection alone cannot reveal the tract’s full extent. The choice of imaging depends on the infant’s age.
For newborns and very young infants, an ultrasound is frequently the first imaging tool used. Ultrasound can often visualize the entire length of the tract from the skin toward the spine. For a more definitive view, magnetic resonance imaging (MRI) is the standard. An MRI provides clear, high-resolution images of soft tissues, allowing doctors to see the tract’s termination point with high accuracy and confirm if it connects to the dura mater or is associated with other underlying conditions.
An MRI is also useful for identifying related abnormalities that can occur with a dermal sinus tract. These can include inclusion cysts, such as dermoid or epidermoid cysts, which are benign masses that can form at the end of the tract. The imaging also helps diagnose a tethered spinal cord, a condition where the spinal cord is abnormally attached to the surrounding tissues, restricting its movement.
Surgical Intervention and Rationale
The standard treatment for a dermal sinus tract that extends into deep tissue is complete surgical removal. The decision to operate is based on preventing serious complications from the tract’s connection. This prophylactic surgery aims to avert future health problems. The surgery involves a neurosurgeon carefully excising the entire length of the tract to close the pathway permanently.
A primary reason for surgery is the risk of infection. The tract can act as a conduit, allowing bacteria from the skin surface to travel into the spinal canal. This can lead to severe infections such as meningitis (an inflammation of the membranes surrounding the brain and spinal cord) or a spinal abscess. These conditions can cause lasting neurological damage, making preventative removal important.
Surgery also addresses the mechanical issues that can be associated with these tracts. A dermal sinus tract can be linked to a tethered spinal cord. This tension can stretch and damage the spinal cord over time, leading to neurological symptoms like weakness in the legs, loss of sensation, and problems with bladder or bowel control. By surgically removing the tract and releasing the tether, surgeons can prevent the onset or progression of these neurological deficits.
Post-Surgery Outlook and Care
Following the surgical removal of a dermal sinus tract, the outlook for most children is excellent. The surgery is a definitive cure, and once the tract is excised, the risk of related infections or neurological problems is eliminated. The recovery process is straightforward, with a short hospital stay focused on monitoring for any signs of infection and ensuring the surgical incision heals properly.
Parents will receive specific instructions for wound care at home, which involve keeping the area clean and dry. Follow-up appointments with the surgical team are scheduled to check on the healing process and the child’s neurological function. When a tract is treated early, before any infections or neurological symptoms have occurred, most children experience no further issues related to the condition and are expected to develop normally.