Histological hair removal study by ruby or alexandrite laser with comparative study on the effects of wavelength and fluence.
BACKGROUND
Several different laser systems are currently used to remove unwanted hairs. In this study, we studied follicular changes following hair removal with ruby or alexandrite lasers at different fluences.


METHODS
Unwanted hairs were treated with a ruby laser (Chromos 694, ICN PhotonIcs, UK) at 10, 14 or 18 J/cm2 or with an alexandrite laser (LPIR, Cynosure, USA) at 11, 14 or 17 J/cm2. A 3 mm skin punch biopsy was taken immediately after each laser exposure and also 1 month later. Specimens were stained for histological observation. They were observed using immunohistochemistry with antibodies recognizing factor VIII related antigen or PCNA, and also by the TUNEL method. Similarly, electron microscopic observation was examined.


RESULTS
Immediately after the laser exposure, moderate follicular damage was observed following treatment with either type of laser. One month later, cystic formation of hair follicles and foreign body giant cells were observed in skin treated with either type of laser. A similar fluence with either laser treatment resulted in similar histological changes.


CONCLUSIONS
In this study, the histological changes following treatment with a ruby or an alexandrite laser at the same fluence are similar.
Kato
Tokue
T
Department of Dermatology, Nippon Medical School, Tokyo, Japan.
Omi
Tokuya
T
Naito
Zenya
Z
Hirai
Takashi
T
Kawana
Seiji
S
D000328:Adult; D001608:Beryllium; D006197:Hair / Q000473:pathology* / Q000648:ultrastructure; D006204:Hair Removal; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000295:instrumentation; D053685:Laser Therapy; D007834:Lasers / Q000145:classification*; D008875:Middle Aged; D018809:Proliferating Cell Nuclear Antigen / Q000648:ultrastructure
D018809:Proliferating Cell Nuclear Antigen; C112654:alexandrite; D001608:Beryllium