Prospective controlled clinical and histopathologic study of hidradenitis suppurativa treated with the long-pulsed neodymium:yttrium-aluminium-garnet laser

BackgroundHidradenitis suppurativa (HS) is a chronic inflammatory disease involving the intertriginous areas.ObjectiveWe sought to conduct clinical and histopathologic evaluation of the efficacy of long-pulsed neodymium:yttrium-aluminium-garnet laser treatment for HS.MethodsWe conducted a prospective, randomized, right-left within-patient controlled trial for HS (n = 22). Four monthly laser sessions were performed. Disease activity was measured at baseline, and treatment response was assessed before each laser session and monthly for 2 months after the completion of laser treatment, using a modified scoring system based on Sartorius score. Histologic examination was performed at baseline, immediately after laser treatment, and at 1 and 4 weeks after treatment. A patient questionnaire was circulated on the last visit to assess patients' level of satisfaction.ResultsThere was progressive improvement in disease activity, most significantly during the 4 months of treatment, which was maintained during the 2-month posttreatment follow-up period. Averaged over all anatomic sites, the percent improvement was 72.7% on the laser treated side, and 22.9% on the control side (P < .05). Histologic examination showed an initial acute neutrophilic infiltrate. Granulomatous inflammation was present on follow-up biopsy specimens 4 weeks later. An inflammatory infiltrate surrounded the hair shaft remnants, denoting destruction of hair follicles.LimitationsSmall sample size was a limitation.ConclusionsLong-pulsed neodymium:yttrium-aluminium-garnet laser, together with topical benzoyl peroxide and clindamycin, is significantly more effective than topical benzoyl peroxide and clindamycin alone for the treatment of HS. Preliminary review of histopathology suggests the mechanism of action is destruction of the hair follicle. The overall success of the treatment in both clearing pre-existing lesions and preventing new eruptions, coupled with high patient satisfaction, makes the neodymium:yttrium-aluminium-garnet laser a promising treatment advance for this highly disabling condition.