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Hypertrichosis paradoxical by laser for hair removal

Hipertricosis paradójica 1

Dr. Dayana Arenas*

  • Resident 3 in dermatology Federico Lleras Acosta Dermatology Center, Unisanitas
A High population of medium-caliber hair with few coarse hairs. B Three months after two sessions with Alexandrite laser. C Three months after the third session with Alexandrite laser, clear paradoxical stimulation. D After electrolysis of 1338 hairs

Depilación

Hair removal

This is a 55-year-old patient who started treatment for hair removal of the upper lip and chin in 2014, during which time 12 sessions were performed with Diode 810, 800 and Alexandrite lasers. At an average interval between sessions of 30 days, a reduction in hair thickness and density of more than 50% was achieved at 90 days. In the second year, it was decided to increase the hair removal surface to the neighboring areas of the cheeks, preauricular regions, anterior neck and earlobes. 10 sessions were performed with Diode 760 and Alexandrite 755 lasers, this time at longer intervals than in the first year of treatment (69-124 days). The reduction in hair population was maintained in all areas, but hair thickening and increased length were observed in the anterior region of the neck and ear lobes, findings that are interpreted as paradoxical hair growth due to laser.

The presence of more hair than before in the areas treated with laser is believed to be due to the prolongation of the anagen phase, observable by the growth of hair in length and thickness, and can in fact be exploited during laser hair removal in areas with a good prognosis. It is interesting that the phenomenon is more frequent on the face and neck of women than would be expected to occur in men. It is observed on the thighs and forearms but not on the legs, and it is observed in areas adjacent to the hair removal area in the presence of abundant, medium-thick hair. It is observed more in brown than black skin tones, especially if the skin is darker, and it is sometimes observed more in overweight patients. It is observed with all types of lasers and especially IPLs.

In the routine use of lasers, it is common to see that the greatest reduction is related to the use of greater power, good coverage in passes and adequate pulse lengths. There are late and additional reductions that have been observed even after one year of the sessions (1-3). There also seems to be an apoptotic induction.

The cause of paradoxical growth is that the laser, for whatever reason, does not destroy the follicles. (subtherapeutic injury) (4-6)

For the phenomenon to be observable, long periods of time must occur, beyond three months. It has been described that at least three sessions must have been performed. The phenomenon tends to persist for years and is most evident in the population with medium and thin hair, but not in thick hair. Areas of hair with little color can also take on a greater hair color.

We prefer to use radiofrequency hair removal under a microscope for this case. Our current practice is that cases like this only merit removal of thick hairs with electrolysis and not with laser.

LITERATURE

  1. Alvarez -Ríos Monitoring of armpit hair removal – Repository of the University of Rosario
  2. Ballesteros- Ríos Long-term follow-up of laser hair removal – Repository of the University of Rosario
  3. Sanchez – Ríos Long-term follow-up of facial hair removal – Repository of the University of Rosario
  4. Desai S, Mahmoud B, Bhatia A, Hamzavi I. Paradoxical hypertrichosis after laser therapy: a review. Dermatol surg 2010;36:291–298
  5. Lolis MS, Marmur ES. Paradoxical effects of hair removal systems: a review. J Cosmet Dermatol. 2006 Dec;5(4):274-6.
  6. Honeybrook A, Crossing T, Bernstein E, Bloom J, Woodward J. Long term outcome of a patient with paradoxical hypertrichosis after laser epilation. J Cosmet Laser Ther. 2018 Jun;20(3):179-183

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