Laser for the Treatment of Hidradenitis Suppurativa

Keywords:laser, fibers, surgical,  Time:01-12-2015

ABSTRACT

Besides surgically excising affected areas, effective treatments are currently lacking. The long-pulsed neodymium:yt- trium-aluminium-garnet (Nd:YAG) laser fibers is a device that has traditionally been used for hair removal, but has recently shown promise in clearing old lesions of HS and preventing new eruptions. In accordance with studies in the current literature, we hypothesize that the Nd:YAG laser will significantly improve subjects with hidradenitis suppurativa compared to standard, uninvasive treatment with topical antibiotics [1,2]. Study aims include: to treat subjects with hidradenitis suppurativa with Nd:YAG laser therapy once monthly for 3 consecutive months, with a one month follow- up; to compare the effectiveness of Nd:YAG treatment on one side of the subject (e.g., right) to treatment with topical antibiotics on the subject’s other side (e.g., left); to assess treatment response using a visual analogue scale; to assess subject satisfaction with treatment using a questionnaire; and to photodocument treatment response at each visit.

1. Introduction

Hidradenitis Suppurativa (HS) is a recurrent and chronic inflammatory disease which can be disfiguring to patients. Usually patients present with tender inflammatory abscesses of the flexures, including the axillary, infra- mammary, and inguinal areas. Scarring and tract formation are prominent features. Females seem to be more often affected than males. Patients are usually post pubertal. The chronic and scarring nature of the disease often leads to significant impacts on the quality of life in these patients [1,2]. HS was first described by Velpeau, a French physician, in 1839. He was also the first to hypothesize that the di- sease was related to purulent inflammation of the sweat glands, later thought to be mainly inflammation of apocrine [2]. More recent data however, supports the theory of follicular occlusion as the predominant feature with apocrine involvement a secondary feature. Bacterial co- lonization is also likely a secondary event which may exacerbate disease. Other factors which may be associated, but not etiologic, include smoking and obesity [2]. The prevalence of HS is estimated at about 1% of the population, but unfortunately there are limited effective treatment options [3]. Current treatment options include topical or systemic antibiotics, isotretinoin, dapsone, biological agents, and surgical interventions. Increasing interest in the use of biologics has led to several recent studies, albeit with only limited numbers of patients. Infliximab was shown to be effective in small studies; however, its use is limited by both adverse effects and cost. Adalimumab, according to a recent review, has not shown consistent results supporting its use despite its growing popularity although it has been well tolerated with no serious side effects reported in any of the studies. Traditional surgical intervention has been excision of the affected areas with variable recurrence rates and high associated morbidity. Newer approaches include the CO2 and Nd:YAG surgical lasers fibers both with promising results [4]. A study performed by Tierney et al in HS patients with moderate disease showed a 65.3% improvement in severity of disease after 4 monthly treatments with Nd:YAG laser. They theorized that the hair follicle was the nidus for inflammation and that destruction of the follicle would lead to improvement. They were able to support this theory with histopathologic evidence that the laser worked through selective photothermolysis of the follicular unit with a reduction in inflammatory lesions [1].

Based on the success of this study and others like it recently in the literature, we decided to further explore the efficacy of the Nd:YAG laser in treatment of patients with HS. Our study was unique in that we recruited patients even with minimal disease as the Nd:YAG laser has a very high safety profile with essentially no risk to the patients; therefore, justifying its use in even minimal disease to prevent scarring and tract formation. Our goals were to treat patients with HS with Nd:YAG laser therapy once monthly for 3 consecutive months and reevaluate after one month, to compare the effectiveness on one side (treatment side) of the patient to the other side (control side), to assess treatment response using a visual analogue scale, to assess subject satisfaction with a subject questionnaire, and to photodocument treatment response at each visit.

2. Methods

Six patients (5 women and 1 man) ages 19 to 54 carrying a clinical diagnosis of hidradenitis suppurativa were enrolled initially in this study, performed at the University of Texas Medical Branch in Galveston, Texas from Fe- bruary 2011 through February 2012. The study was approved by the UTMB institutional review board and was in accordance with the Declaration of Helsinki. A sample size of 5 was calculated to have 80% power to detect a difference in means of 23.400 (e.g. a First condition mean, μ1, of 31.000 and a Second condition mean, μ2, of 7.600), assuming a standard deviation of differences of 12.000, using a paired t-test with a 0.050 two-sided significance level.  

Patients were included if they had at least Hurley stage I disease of their axilla (abscess formation without sinus tracts and cicatrization) [5]. Patients were excluded for the following reasons: pregnancy, previous surgical treatment to affected areas, or any concomitant systemic therapy. Patients on systemic therapy were allowed to enter the study as long as they discontinued the therapy at least 2 weeks prior to the initiation of the study laser protocol.  

First the treatment side (right vs. left axilla) was chosen using a computerized randomization tool. Three monthly laser treatments were then performed using a single pass of the long pulsed 1064-nm Nd:YAG laser (Cutera Inc., Brisbane, California) with a one month follow up after completion of the three treatments, for a total study period of four months. A topical cooling gel was employed using the standard laser treatment protocol, but no anesthetics were used. A contact metal-tipped cooling device was used on the treatment areas immediately before and after irradiation. The laser settings were chosen based on the patient’s Ftizpatrick skin type per Cutera’s recommendations. Patients were given an aftercare instructions handout. Topical 1% Clindamycin gel was used on both the control and treatment sides. After the study period of 4 months, patients were allowed to continue receiving treatment to the treatment side and initiate treatment to the control side at no cost if they so desired.  Patients were contacted within 48 hours of treatment to assess for adverse events. Patients were also evaluated at the follow up visits by the treating physician for any development of adverse events, including pigmentary alterations.  Photos were taken of treated and untreated sides with and without flash prior to each session and at the one month follow up. Photographs were then evaluated by both a blinded physician and resident. Initially the modified HS LASI score designed by Sartorius et al. [6] was to be the evaluation tool; however, it was difficult to use this scoring system with the photographs, and a new modified score was created by our center based on the Sartorius score (Table 1).  In addition, patients were asked to fill out a subject assessment questionnaire after each treatment visit. The questionnaires assessed the patients’ overall satisfaction with the treatment and their subjective improvement as well as assessing for any side effects of therapy.  A paired t-test was done to compare the mean percentage of change for both treated and control sites for each patient from baseline to the fourth month. Of note the scores between the physician scorer and resident scorer were not different based on t tests; therefore, we averaged across scorers. The p value was calculated for the mean percentage of change and a value of less than 0.05 indicates statistical significance for the study.

3. Results

A total of 5 patients completed this 4 month study. One patient (19 year old female) withdrew prior to beginning the study secondary to scheduling conflicts. The mean age was 37.6 years, with 80% females (n = 4) and 20% males (n = 1). Fitzpatrick skin types ranged from II to V, with 3 patients having type II-III, and one patient each having type IV and type V. Only axillary disease was treated in this study.