Title: Hair growth cycle affects hair follicle destruction by ruby laser pulses.
Authors: Lin TY, Manuskiatti W, Dierickx CC, Farinelli WA, Fisher ME, Flotte T, Baden HP, Anderson RR
Journal: J Invest Dermatol 1998 Jul;111(1):107-13
PMID: 9665395, UI: 98328332
Affiliated institution: Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
It has been shown that normal mode ruby laser pulses (694 nm) are effective in selectively destroying brown or black pigmented hair follicles in adult Caucasians. This study investigated how the various stages of the hair follicle growth cycle influence follicle destruction by ruby laser treatment, using a model of predictable synchronous hair growth cycles in the infantile and adolescent mice. A range of ruby laser pulse fluences was delivered during different stages of the hair growth cycle, followed by histologic and gross observations of the injury and regrowth of hair. Actively growing and pigmented anagen stage hair follicles were sensitive to hair removal by normal mode ruby laser exposure, whereas catagen and telogen stage hair follicles were resistant to laser irradiation. Selective thermal injury to follicles was observed histologically, and hair regrowth was fluence dependent. In animals exposed during anagen, intermediate fluences induced nonscarring alopecia, whereas high fluences induced scarring alopecia. The findings of this study suggest treatment strategies for optimal laser hair removal.
Selected references (14 of 28 shown; others primarily discuss hair growth in animals)
1. Anderson RR, Parrish JA. The optics of human skin. J Invest Dermatol 1981;77:13-9.
2. Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science 1983;220:524-7.
3. Cavanagh JB, Gregson M. Some effects of a thallium salt on the proliferation of hair follicle cells. Br J Dermatol 132:367-375, 1995
4. Chase HB. Growth of the hair. Physiol Rev 34:113-126, 1954
5. Chase HB, Montagna W. Relation of hair proliferation to damage induced in the mouse skin. Proc Soc Exper Biol Med 76:35-37, 1951
6. Cotsarelis G, Sun TT, Lavker RM. Label-retaining cells reside in the bulge area of pilosebaceous unit: implications for follicular stem cells, hair cycle and skin carcinogenesis. Cell 1990;61:1329-37.
7. Dierickx CC, Grossman MC, Farinelli WA, Anderson RR. Permanent hair removal by normal-mode ruby laser Arch Dermatol, 1998
8. Ellinger F. Effects of ionizing radiation on growth and replacement of hair. Ann New York Acad Sci 53:682-687, 1951
9. Grossman MC, Dierickx C, Farinelli W, Flotte T, Anderson RR. Damage to the hair follicles by normal-mode ruby laser pulses. J Am Acad Dermatol 1996;35:889-95
10. Kvedar JC, Gibson M, Krusinski PA. Hirsutism: evaluating treatment. J Am Acad Dermatol 12:215-225, 1995
11. Paus R, Stenn KS, Link RE. Telogen skin contains an inhibitor of hair growth. Br J Dermatol 122:777-784, 1990
12. Rauch H. Effects of topical applications of chemical agents on hair development. Physiol Zool 25:268-272, 1979
13. Richards RN, Meharg GE Electrolysis: observations from 13 years and 140,000 hopurs of experience. J Am Acad Dermatol 33:662-666, 1995
14. Tosi A Misciali C, Piraccini BM, Peluso AM, Bardazzi F. Drug-induced hair loss and hair growth. Incidence, management and avoidance.Drug Saf 10:310-317, 1994
