Laser Surgery
Paradoxical hypertrichosis after laser epilation

https://doi.org/10.1016/j.jaad.2004.06.054Get rights and content

Objective

Hair removal using lasers or broadband intense pulsed light has become one of the most ubiquitous medical procedures. At our center a small proportion of patients have spontaneously reported what they believed to be increased hair growth at sites of previous laser epilation. We sought to retrospectively review the prevalence and features of this paradoxical effect.

Methods

This was a single center, retrospective study that included all patients who underwent laser hair removal during a 4-year period with a long-pulsed alexandrite laser. All cases of laser-induced hypertrichosis were assessed clinically by history, examination, and laboratory tests, and confirmed by review of serial clinical photographs taken during the course of the laser treatments. The clinical features of patients with postlaser hypertrichosis were compared with 50 patients randomly selected from among all those who had undergone laser hair removal at our center (n = 489).

Results

Of 489 patients, 3 (0.6%, 95% confidence interval: 0.01-1.9%) treated with the long-pulsed alexandrite laser (755 nm) reported increased hair after laser hair epilation. There was a trend for this adverse effect to occur in darker skin phototypes (IV) and with black hair as compared with the unaffected comparison group (n = 50). However, the small number of cases (n = 3) did not provide sufficient power to adequately test factors such as age, sex, treatment settings, and number of treatments statistically.

Conclusion

Postlaser hair removal hypertrichosis is a real but rare occurrence in our experience.

Section snippets

Methods

This retrospective study included all patients who underwent laser hair removal at a single center between June 1999 and June 2003. A long-pulsed 755-nm alexandrite laser (Epitouch 5100, Lumenis Ltd [formerly Sharplan Medical Systems], Santa Clara, CA) was used for all patients. Most of the laser procedures were done primarily by trained nurses under the direct supervision of dermatologists; the remainder of the procedures were performed by board-certified dermatologists. Patients were included

Case 1

A 39-year-old woman of Mediterranean descent with type IV skin and black hair underwent laser hair removal to her face in June 1999. At an initial laser setting of 7-mm spot size, 30-millisecond pulse duration, and 23 J/cm2 fluence, there was a good immediate release of exposed hairs, but this immediate hair release became progressively more resistant with successive sessions. She reported a gradual increase in facial hair despite ongoing laser sessions. This became evident on clinical

Results

Of 489 patients, 3 reported postlaser epilation hypertrichosis during a 4-year period (0.6%, 95% confidence interval: 0.01-1.9%). In those patients, the laser treatments were considered the most likely cause for hypertrichosis, because hair growth occurred exclusively at treated sites. All 3 of our patients had black hair and skin phototype IV. The median age, race, skin type, hair color, and treatment settings for these individuals and the comparison group are summarized in Table I. As

Discussion

It was several years after the FDA approved laser hair removal devices when posttreatment hypertrichosis, a rare paradoxical effect of this type of treatment, arose. Moreno-Arias et al2 and Hirsch et al3 independently reported a collection of cases where increased hair growth developed after hair epilation procedures with intense pulse light and 755-nm alexandrite laser, respectively. Likewise in our center, we have noticed this rare event for which we have sought possible precipitating

References (11)

  • K.J. Lucas

    Finasteride cream in hirsutism

    Endocr Pract

    (2001)
  • E.L. Tanzi et al.

    Laser in dermatology: four decades of progress

    J Am Acad Dermatol

    (2003)
  • C.A. Moreno-Arias et al.

    Side-effects after IPL photodepilation

    Dermatol Surg

    (2002)
  • R.J. Hirsch et al.

    Hair removal induced by laser hair removal

    Lasers Surg Med

    (2003)
  • C. Handrick et al.

    Comparison of long-pulsed diode and long-pulsed alexandrite lasers for hair removal: a long-term clinical and histologic study

    Dermatol Surg

    (2001)
There are more references available in the full text version of this article.

Funding sources: None.

Conflicts of interest: None identified.

Presented in part at the Fourth Intercontinental Meeting of Hair Research Societies, Berlin, Germany, June 18, 2004.

View full text