Ann Dermatol.  2015 Oct;27(5):517-522. 10.5021/ad.2015.27.5.517.

Efficacy and Safety of Hair Removal with a Long-Pulsed Diode Laser Depending on the Spot Size: A Randomized, Evaluators-Blinded, Left-Right Study

• Jo SJ
• Kim JY
• Ban J
• Lee Y
• Kwon O
• Koh W

• KMID: 2171451
• DOI: http://doi.org/10.5021/ad.2015.27.5.517

Abstract

BACKGROUND
The efficacy of the long-pulsed diode laser (LPDL) in hair removal is determined with various physical parameters. Recently, LPDLs with a larger spot size are commercially available; however, the independent effect of spot size on hair removal has not been studied.
OBJECTIVE
This study aimed to compare the efficacy of the LPDL in hair removal depending on the spot size.
METHODS
A randomized, evaluators-blind, intrapatient comparison (left vs. right) trial was designed. Ten healthy Korean women received three hair removal treatment sessions on both armpits with the 805-nm LPDL and followed for 3 months. A 10x10 mm handpiece (D1) or a 10x30 mm handpiece (D3) was randomly assigned to the right or left axilla. The fluence, pulse duration, and epidermal cooling temperature were identical for both armpits. Hair clearance was quantified with high-resolution photos taken at each visit. Postprocedural pain was quantified on a visual analogue scale. Adverse events were evaluated by physical examination and the patients' self-report.
RESULTS
The mean hair clearance at 3 months after three treatment sessions was 38.7% and 50.1% on the armpits treated with D1 and D3, respectively (p=0.028). Procedural pain was significantly greater in the side treated with D3 (p=0.009). Serious adverse events were not observed.
CONCLUSION
Given that the pulse duration, fluence, and epidermal cooling were identical, the 805-nm LPDL at the three times larger spot size showed an efficacy improvement of 29.5% in axillary hair removal without serious adverse events.

Keyword

Hair; Hair removal; Long pulsed diode laser; Laser spot size

MeSH Terms

Axilla
Female
Hair Removal*
Hair*
Humans
Lasers, Semiconductor*
Physical Examination

Figure

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  Fig. 1 Photographs of axillary areas treated with the small- and large-spot long-pulsed diode laser at baseline, after three treatment sessions, and at the 6-month follow-up in the same subject.

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  Fig. 2 Hair clearance of long-pulsed diode laser-treated axillary areas (A) in all 10 subjects and (B) in three subjects followed for up to 6 months after completing the three sessions. *p<0.05 between areas treated with a 10×10 mm handpiece (D1) and a 10×30 mm handpiece (D3).

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