Augmentation de la pilosité après laser épilatoire ou hypertrichose paradoxale
L'hypertrichose paradoxale (poussée de poils à distance de la zone épilée) est une complication rare (0,6 à 10%) qui survient plus souvent sur le visage des patients dont la peau est mate. Pour une épilation normale, il faut compter normalement 3 à 8 séances mais le nombre de séance est d'autant plus important que les poils sont fins. Les lampes intenses pulsées marchent moins bien et nécessitent souvent beaucoup plus de séances que le laser alexandrite.
Ci dessous des références bibliographiques récentes
Dermatol Surg. 2010 Mar;36(3):291-8. Epub 2010 Jan 19.
Paradoxical hypertrichosis after laser therapy: a review.
Desai S, Mahmoud BH, Bhatia AC, Hamzavi IH.
Department of Dermatology, Loyola University, Maywood, Illinois 60563, USA. [email]shraddha.desai@dupagemd.com[/email]
Abstract
BACKGROUND: Laser hair removal is a safe and effective procedure for the treatment of unwanted body hair but is not exempt from side effects. A rare but significant adverse effect with this treatment modality is paradoxical hypertrichosis. OBJECTIVE: To evaluate the potential etiologies, risk factors, related laser types, and treatment options for the development of excess hair after laser therapy. MATERIALS AND METHODS: An analysis of previously published case studies and review articles along with our own experience was used to gather information regarding this phenomenon. RESULTS: Paradoxical hypertrichosis has a low incidence, ranging from 0.6% to 10%, and most commonly occurs on the face and neck. All laser and light sources have the potential to cause hair induction, especially in individuals with darker skin types (III-VI); with dark, thick hair; and with underlying hormonal conditions. Possible causes include the effect of inflammatory mediators and subtherapeutic thermal injury causing induction of the hair cycle. Treatment for paradoxical hypertrichosis is laser therapy of the affected area. CONCLUSIONS: Paradoxical hypertrichosis is a rare side effect of laser hair removal; the pathogenesis of this event remains widely unknown. We recommend further large-scale studies to investigate this effect. The authors have indicated no significant interest with commercial supporters.
J Cosmet Dermatol. 2006 Dec;5(4):274-6.
Paradoxical effects of hair removal systems: a review.
Lolis MS, Marmur ES.
Department of Dermatology, Mount Sinai School of Medicine, New York, NY 10029, USA. [email]margarita.lolis@mssm.edu[/email]
Abstract
Although a variety of lasers have proven to be clinically effective for long-term hair removal, the use of these lasers has also been associated with undesirable side effects, such as hyper- and hypopigmentation, crusting, erythema, and edema. One notable side effect that seems to be underreported in the literature is the growth of fine dark hair in untreated areas close to the treated ones. This contradictory hypertrichosis is known as the paradoxical effect. In this paper, we review the published reports of the paradoxical effect and offer some possible explanations for this effect. The paradoxical effect has been documented most commonly after the use of induced pulse light and alexandrite lasers. One possible explanation is the activation of dormant hair follicles by suboptimal fluences. Another mechanism may be the synchronization of hair growth cycles by direct light stimulation.
PMID: 17716243 [PubMed - indexed for MEDLINE]
J Am Acad Dermatol. 2005 Jul;53(1):85-8.
Paradoxical hypertrichosis after laser epilation.
Alajlan A, Shapiro J, Rivers JK, MacDonald N, Wiggin J, Lui H.
Division of Dermatology, Vancouver Coastal Health Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
Abstract
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.
PMID: 15965427 [PubMed - indexed for MEDLINE]
Dernière modification par dermatologue ; 24/05/2010 à 10h39.
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Dr Philippe Abimelec, Dermatologue
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