Department of Dermatology, Loyola University, Maywood, Illinois 60563, USA.
Dermatol Surg. 2010 Mar;36(3):291-8. doi: 10.1111/j.1524-4725.2009.01433.x. Epub 2010 Jan 19.
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.
To evaluate the potential etiologies, risk factors, related laser types, and treatment options for the development of excess hair after laser therapy.
An analysis of previously published case studies and review articles along with our own experience was used to gather information regarding this phenomenon.
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.
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.
激光脱毛是一种安全有效的治疗多余体毛的方法，但也并非没有副作用。这种治疗方法的一个罕见但严重的不良反应是反常性多毛症。
评估激光治疗后毛发过度生长的潜在病因、危险因素、相关激光类型和治疗选择。
对已发表的病例研究和综述文章进行分析，并结合我们自己的经验，收集有关该现象的信息。
反常性多毛症的发病率较低，范围为 0.6%至 10%，最常见于面部和颈部。所有激光和光源都有可能引起毛发诱导，尤其是在皮肤类型较深（III-VI）、毛发较黑较粗、存在潜在激素状况的个体中。可能的原因包括炎症介质的作用和亚治疗性热损伤导致毛囊周期的诱导。反常性多毛症的治疗方法是对受影响的区域进行激光治疗。
反常性多毛症是激光脱毛的一种罕见副作用；该事件的发病机制仍广泛未知。我们建议进行进一步的大规模研究来调查这种效应。作者表示没有与商业支持者的重大利益关系。
