ABSTRACT
BACKGROUND: Lasers and light sources are now used worldwide for permanent or prolonged hair removal. Patients now prefer lasers and light sources for hair removal because of their noninvasiveness and fewer reported side effects. OBJECTIVE: To study and report on leukotrichia that developed following application of intense pulsed light (IPL). METHODS: From February 9, 2001 to February 14, 2002 a total of 821 patients were treated for unwanted hair. The system used was a noncoherent IPL system, with a 650 nm flashlamp filter; the parameters used varied with different Fitzpatrick skin types. The patients were treated monthly, with the rate of hair loss, measured by hair counts, and possible side effects recorded. RESULTS: Twenty-nine of 821 patients treated developed leukotrichia. Thirteen patients had no white or gray hairs before IPL therapy; the remaining 16 patients, who had few white hairs before treatment reported accelerated development of new white hairs starting after the first or second IPL therapy. Restoration of hair color occurred in 9 patients and the remaining 20 patients had no improvement or worsening of the condition within the next 2-6 months. CONCLUSION: Temporary or permanent leukotrichia may develop following IPL and laser hair removal therapy. This finding may be explained by the difference in the thermal relaxation times of melanocytes and germinative cells. The light absorbed and the heat produced by melanin may be sufficient enough to destroy or impair the function of melanocytes but insufficient to damage the hair follicle cells.
