Quantitative assessment of growing hair counts, thickness and colour during and after treatments with a low-fluence, home-device laser: a randomized controlled trial

TY - JOUR

T1 - Quantitative assessment of growing hair counts, thickness and colour during and after treatments with a low-fluence, home-device laser

T2 - a randomized controlled trial

AU - Thaysen-Petersen, D

AU - Barbet-Pfeilsticker, M

AU - Beerwerth, F

AU - Nash, J F

AU - Philipsen, P A

AU - Staubach, P

AU - Haedersdal, M

N1 - © 2014 British Association of Dermatologists.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Background At-home laser and intense pulsed-light hair removal continues to grow in popularity and availability. A relatively limited body of evidence is available on the course of hair growth during and after low-fluence laser usage. Objectives To assess growing hair counts, thickness and colour quantitatively during and after cessation of low-fluence laser treatment. Methods Thirty-six women with skin phototypes I-IV and light to dark-brown axillary hairs were included. Entire axillary regions were randomized to zero or eight self-administered weekly treatments with an 810-nm home-use laser at 5·0-6·4 J cm-2. Standardized clinical photographs were taken before each treatment and up to 3 months after the final treatment for computer-aided quantification of growing hair counts, thickness and colour. Results Thirty-two women completed the study protocol. During sustained treatment, there was a reduction in growing hair that reached a plateau of up to 59%, while remaining hairs became up to 38% thinner and 5% lighter (P < 0·001). The majority of subjects (77%) reported 'moderately' to 'much less hair' in treated than untreated axilla, and assessed remaining hairs as thinner and lighter (≥ 60%). After treatment cessation, hair growth gradually returned to baseline levels, and 3 months after the final treatment the count and thickness of actively growing hair exceeded pretreatment values by 29% and 7%, respectively (P ≤ 0·04). Conclusions Sustained usage of low-fluence laser induced a stable reduction of growing hair counts, thickness and colour. The reduction was reversible and hairs regrew beyond baseline values after cessation of usage. Computer-aided image analysis was qualified for quantification of hair counts, thickness and colour after laser epilation.

AB - Background At-home laser and intense pulsed-light hair removal continues to grow in popularity and availability. A relatively limited body of evidence is available on the course of hair growth during and after low-fluence laser usage. Objectives To assess growing hair counts, thickness and colour quantitatively during and after cessation of low-fluence laser treatment. Methods Thirty-six women with skin phototypes I-IV and light to dark-brown axillary hairs were included. Entire axillary regions were randomized to zero or eight self-administered weekly treatments with an 810-nm home-use laser at 5·0-6·4 J cm-2. Standardized clinical photographs were taken before each treatment and up to 3 months after the final treatment for computer-aided quantification of growing hair counts, thickness and colour. Results Thirty-two women completed the study protocol. During sustained treatment, there was a reduction in growing hair that reached a plateau of up to 59%, while remaining hairs became up to 38% thinner and 5% lighter (P < 0·001). The majority of subjects (77%) reported 'moderately' to 'much less hair' in treated than untreated axilla, and assessed remaining hairs as thinner and lighter (≥ 60%). After treatment cessation, hair growth gradually returned to baseline levels, and 3 months after the final treatment the count and thickness of actively growing hair exceeded pretreatment values by 29% and 7%, respectively (P ≤ 0·04). Conclusions Sustained usage of low-fluence laser induced a stable reduction of growing hair counts, thickness and colour. The reduction was reversible and hairs regrew beyond baseline values after cessation of usage. Computer-aided image analysis was qualified for quantification of hair counts, thickness and colour after laser epilation.

KW - Adolescent

KW - Adult

KW - Female

KW - Hair

KW - Hair Color

KW - Hair Removal

KW - Humans

KW - Laser Therapy

KW - Middle Aged

KW - Photography

KW - Self Care

KW - Treatment Outcome

KW - Young Adult

U2 - 10.1111/bjd.13254

DO - 10.1111/bjd.13254

M3 - Journal article

C2 - 25039260

SN - 0007-0963

VL - 172

SP - 151

EP - 159

JO - British Journal of Dermatology

JF - British Journal of Dermatology

IS - 1

ER -