Cosmetology and Dermatology

Biography

Biography: Forugh Ghaedi

Abstract

Purpose: In order to evaluate increasing patients' complaints of change in the appearance of melanocytic nevi following hair removal laser, we planned this study to describe dermoscopic changes that happen on acquired junctional melanocytic nevi after using photo-depilation methods.

Method: In this prospective study, 66 melanocytic nevi in 27 patients were chosen. A Dermoscopic image  was taken at first and 3 months after 1 session of hair removal laser. Then the images compared with each other and changes in nevi were noted.

 Results: there were some alterations including changes in size in 33%, color in 63.6%, asymmetry in 12.1%, reticular pattern in 92.5%, dots and globules pattern in 69.32% and regression in 3% of nevi.

 Conclusions: Hair removal laser could induce some changes in appearance of acquired junctional melanocytic nevi. Dermoscopic study before and after the process, could help to avoid unnecessary excision of suspected lesions. 

Keywords: melanocytic nevi, dermoscopic changes, hair removal laser, photoepilation

Introduction:

Increasing demand for rapid and non-invasive depilation lead generating Intense Pulsed Light (IPL) systems, afterward lasers such as Alexandrite, Diode and Nd-Yag Laser (1, 2).

Target of lasers in the hair removal lasers is melanin in hair follicles, an endogenous chromophore that absorbs energy of beats with wavelengths near 600 to 1200 nm, transfers this heat to hair follicle and destroys it. Laser beam would not destroy the epidermal melanin before arriving to its target, hair follicle melanin in dermis, as the ratio of melanocytes to keratinocytes in epidermis is less than hair follicle and epidermal melanocytes contain fewer and smaller melanosomes than those in the hair follicles melanocytes. Furthermore, selecting appropriate wavelengths and wide spot size in addition to using cooling systems helps protection of epidermal melanocytes. Therefore, hair removal laser is considered a safe procedure with minimal epidermal side effects (3).

 Considering the fact that melanocytic nevi composed of numerous heavily melanized melanocytes, these structures could absorb some part of the beat energy at the surface of skin before arriving at melanin of hair follicles in dermis. Therefore, some changes could happen in their appearance when applying these instruments for treating superficial melanocytic lesions. (4, 5)

There are some case reports that show regression or dermoscopic changes in size, pigmentation and pattern of melanocytic nevi after photo-depilation with IPL or laser systems. Furthermore, some of them reported changes of nevi in patients with past personal or family history of dysplastic nevi or malignant melanoma, although histologic changes did not have enough evidence for malignant transformation. (6-12)

In addition to these scattered reports, recently Guicciardi et al evaluated clinical and dermoscopic effects of photoepilation on 73 melanocytic nevi in a prospective study. They noted pigmentation changes and both complete regression and progressive growth but not malignant modification. (13)

As far as we know, there are limited studies about the effect of hair removal lasers on melanocytic nevi in literature review. So we planned this assay in order to help the decision if hair removal laser avoidance in the sites of melanocytic nevi is necessary or not.

Methods and Materials:

Patients

Females referred to Laser Clinic of Razi Dermatology Hospital, Tehran, Iran between October 2018 and October 2019 that supposed to perform a hair removal laser for the first time participated in this cross-sectional study by applying a simple sampling method.  

Methods

 Alexandrite Laser (GENTLEMAX PRO^®755 nm, Candela, Massachusetts, USA, 18 mm spot size, 14-16 mj fluence) was used for hair removal. We examined the skin of candidates to detect junctional melanocytic nevi at the sites of supposing to Laser, if it exists, we assessed it by dermoscope (Fotofinder medicam 1000, Germany) and took photograph and dermoscopic images of it before initiation of Laser. Nearly three months after laser epilation, the same nevi were reanalyzed and dermoscopic images were taken to compare any change in size, color, symmetry, reticulation pattern, dot/globule pattern and regression of nevi before and following the hair removal laser.

Statistical analysis

Chi-Square and Independent T-tests were used to compare qualitative and Quantitative variables, respectively. Two-tailed P-value < 0.05 was considered as statistically significant. SPSS software version 18 was used for all statistical analyses.

 Ethical consideration

All participants filled informed consent and the Ethics Committee of Tehran University of Medical Sciences approved the protocol of study. 

Results:

Twenty-seven women with age of 29.95 ± 5.81 years participated in the study. Sixty-six junctional melanocytic nevi in their bodies were analyzed before the first session of hair removal laser and 3 months after that.  

Fifty-nine nevi (90%) were located on the upper part of the body and seven (10%) on the lower part.

Patients Fitzpatrick skin type was two, three and four in 9 (13.6%), 45 (68.2%) and 12 (18.2%) cases, respectively.

Changes in size:

We observed a decrease in size at least 1 mm in 33% of nevi after hair removal laser, but there was no difference in size in 66%. There was no difference in alteration of size with age, location of nevi and Fitzpatrick skin type, but we detected a significant relation between changes in size and alteration in color (p-value: 0.01), as has been described below. 

Discussion:

Our results revealed that hair removal lasers could induce some changes on acquired junctional melanocytic nevi but none of them showed dermoscopic criteria of malignant transformation. Most changes happened on the reticular and dot/globule patterns in 92.5% and 71.2% of nevi, respectively, Pic(1, 2),   similar to result of the Guicciardi et al. study that reported any degree of pigment network change in 79% of cases.(13)

In our study, nevi became lighter in 43.9% and darker in 19.7% of cases. The same study reported that pigmentation loss occurred in 82% of nevi but also an increased pigmentation at the periphery with central light brown background happened in most of them.(13)

We reported a decrease in nevus size in 33% of cases that observed more frequently in cases with color change.  Interestingly Guicciardi et al reported increase in size in one case with progressive growth and appearance of globules at the periphery of the lesion. Nevertheless, the histological examination showed features of a compound nevus with slight atypia but not obvious malignant transformation. (13)

We observed asymmetry in 12.1% of nevi after hair removal laser; changing in size was the most related variable with this item and it happened in 75% of asymmetric nevi. Guicciardi et al did not report any asymmetry. Whereas they indicated some other changes like Follicular re-pigmentation or telangiectasia that we did not observed, also they reported crusting in 11% of nevi. (13)