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Histological hair removal study by ruby or alexandrite laser with comparative study on the effects of wavelength and
Tokue Kato1, Tokuya Omi, Zenya Naito
1Department of Dermatology, Nippon Medical School, Tokyo, Japan.
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.
Conclusion:
In this study, the histological changes following treatment with a ruby or an alexandrite laser at the same fluence are similar.
