15 Laser Hair Removal

Abstract

Hair removal is one of the most common cosmetic procedures performed today. In 2009, industry revenue for hair removal, either personally or by a practitioner, totaled approximately $244 million. It has been practiced since prehistoric times with specific modifications due to local cultural, religious, as well as personal aesthetic preferences. Ancient Egyptian men shaved hair from their heads and faces to prevent grasping during battle; women in the Middle Ages plucked and shaved hair on their eyebrows and anterior hairline to conform to contemporary standards of beauty. 1 Contemporary demand ranges from cases of hirsutism and hypertrichosis to normally distributed body hair that is unwanted. Hirsutism is abnormal hair growth in women in androgen-dependent sites, whereas hypertrichosis is excess hair growth in a body site (anywhere on the body) independent of hormones.Depilation, the removal of the hair shaft, and epilation, the removal of the hair shaft and bulb, are the two primary methods of hair removal. Shaving is an example of depilation, whereas epilation includes methods such as waxing, electrolysis, and laser hair removal. Epilation hair removal provides results that usually last about 8 weeks; depilation results only last for approximately 2 weeks. 2 Shaving, an extremely cost-efficient and popular method for men's facial hair and women's legs and underarms, does not alter the hair cycle and is a temporary solution to hair growth. 3 Historically, shaving tools have ranged from sharpened animal teeth and flint to modern electric and nonelectric blades.Waxing, which has existed since ancient times, provides temporary hair removal and can treat large areas efficiently, albeit at a risk of skin irritation and pain. 4 Electrolysis results in potentially permanent hair removal by a probe passing an electrical current to destroy the hair follicle. It is however a slow and operator-dependent method with wide-ranging rates of complications such as scars and pigment changes. 5 Laser hair removal utilizes the existing melanin in hair follicles for specific targeting called selective photothermolysis. It is important to appreciate the evolution of hair removal because it guides providers about needs for future improvements as well as motivation for patient demands. 6 Hair Follicle Growth and AnatomyThe hair follicle is a hormonally active structure with specifically programmed growth. It can be divided into three anatomical portions from superficial to deep: infundibulum, isthmus, and inferior segment (▶ Fig. 15.1). The inferior segment is bordered inferiorly by the base of the follicle and extends superiorly to the erector pili muscle. The isthmus extends from the erector pili muscle to the sebaceous gland duct. The infundibulum extends superiorly to the follicular orifice. The dermal papilla supplies proliferating cells at the base of the follicle.Melanocytes, located near the infundibulum, provide the pigment that determines hair color.The hair follicle can be in any one of three different metabolic phases: ana...