Faun Tail Overlying Spinal Dysraphism (Diastematomyelia) at the Mid Thoracic Level: Cosmetic Improvement Achieved with Diode Laser Epilation.

Sir,

Faun tail which represents congenital localized hypertrichosis (with coarse and dark hairs) over the spine is a rare entity and may serve as a cutaneous marker for occult spinal dysraphism. Although the lumbosacral area is most commonly involved, rarely the thoracic and cervical area may also be involved. Separation of the spinal cord into two hemicords is called diastematomyelia and is of two types. The two hemicords are usually symmetric although the length of separation is variable. In Type 1, the two hemicords are separated by an osseous/cartilaginous septum. Type 2 comprises a single dural tube containing two hemicords separated by a fibrous septum.[1]

A 16-year-old girl with Fitzpatrick skin type IV presented with a “faun tail” over the thoracic spine extending from 4 to T12 levels, present since birth [Figure 1]. There was no family history of spinal abnormalities. She was psychologically disturbed by the presence of excess hair over the spinal area and complained of difficulty in interaction with peers.

Figure 1

“Faun tail” over the thoracic spine extending from T4 to T12 levels, present since birth

Neurosurgical evaluation at 7 years of age confirmed the absence of bowel or bladder involvement. MRI study of the thoracic spine showed occult spinal dysraphism at the thoracic level [Figure 2], diagnosed as diastematomyelia with separate dural sac/hemicord with central osseous septum – Type I split cord malformation (SCM). The detailed report is listed in Table 1.

Figure 2

MRI study of the thoracic spine showed occult spinal dysraphism at the thoracic level

Table 1

MRI report prior to surgery

Following excision of the bony spur she has remained asymptomatic troubled only by the cosmetic disfigurement of the “faun tail.”

Treatment was carried out using the 810-nm diode laser LightSheer Duet™ (Lumenis, Inc., Santa Clara, CA, USA) with a 9-mm-square spot, fluences ranging from 17 to 27 J/cm2, 1 Hz, and a pulse-duration of 100 milliseconds. Starting with an initial low fluence (17 J/cm2), there was gradual increment to a fluence of 27 J/cm2. From the fourth sitting onward, a second pass with slightly lower energies (2–4 J/cm2 less than the first pass) was administered soon after completion of the first pass. Cold packs were applied over the treatment area and surrounding area before and after treatment to decrease pain. Sessions were repeated at 4–8 weekly intervals. Minimal hyperpigmentation was observed following treatment with fluences of 26 J/cm2 which subsided with topical hydroquinone 4% cream for 2 weeks. Regrowth of thinner and lighter hairs was seen following 13 sessions. She was satisfied with the cosmetic outcome [Figure 3].

Figure 3

Patchy regrowth of thinner and lighter hairs after 13 sessions

To overcome the psychological problems, cosmetic treatment of the “faun tail” using lasers (ruby laser, alexandrite laser) had been carried out.[2] Electroepilation and intense pulsed light (IPL) epilation have been tried in lumbosacral hypertrichosis but not found to be superior to laser systems for hair removal.[3] Lasers with longer wavelengths like the diode, alexandrite and the 1064 nm Nd:YAG laser are preferable in darker skin types as they cause less pain, epidermal injury and post inflammatory hyperpigmentation seen with lasers with shorter wavelengths. The suitable candidates for alexandrite laser epilation include patients with light skin color (up to Type III) and dark hair, while the diode laser may be safer in darker skin types (Type IV–VI). The long-pulsed diode laser (800–810 nm) has been used extensively for LHR and is safe in patients with Fitzpatrick skin types I–V.[24]

Paradoxical hypertrichosis refers to the excess hair around the previously treated site and is an adverse effect seen with laser treatment but more with IPL.[5]

Cold packs around the treatment area may prevent low fluences from reaching the peripheral follicles and minimize this adverse effect. A double pass with the laser either soon after the first pass or 1 week later with slightly less fluences is thought to prevent paradoxical hypertrichosis.[5] Permanent reduction denotes long-term decreased hair growth with thinner, lighter and finer hairs rather than the total absence of hair growth in the treated site.

After 13 sessions, patchy regrowth of thinner hairs was seen which was cosmetically acceptable. The diode laser is safe and effective for achieving near permanent hair removal in the treatment of the faun tail in darker skin types.