Hair removal by any means is unlikely to decrease in popularity, especially with the advent of laser technology allowing for effective treatment of hypertrichosis and hirsutism. There are many effective laser and intense light sources. Although virtually all skin types can be treated, the ideal target is a dark hair on light colored skin, and treatment of nonpigmented or vellus hairs has been disappointing with this method. The physical hair removal methods will continue to be popular options. The practice of aesthetic medicine should include consideration of offering hair reduction using lasers or light sources.
Dermatologists and plastic surgeons, as well as other aesthetically oriented physicians and licensed aestheticians, provide services for both temporary and permanent forms of hair reduction in a variety of clinical settings. According to the American Society of Plastic Surgeons, laser hair removal alone accounts for $406 million in revenue annually and is the third most popular cosmetic nonsurgical procedure, with 1,280,031 cases done in 2009. Hair removal or reduction methods can be used on any hair-bearing body site, but are most popular in sites of secondary sexual hair areas including the axillae, the pubic area, face, and chest.
Cosmetically disturbing, unwanted hair growth is separated into hirsutism and hypertrichosis and defined as increased hair growth in male secondary sexual areas in a woman, including the mustache, beard, chest, escutcheon, and inner thigh. Hair growth in these areas is restricted to strongly androgen-responsive hair follicles. Hypertrichosis refers to increased growth of terminal hairs in areas normally rich in vellus hairs. This hair growth is beyond the length or density of normally accepted growth in any age, sex, or group. The excess hair may be generalized or localized. Terminal hairs are produced by large hair follicles located in the subcutis. The diameter of individual hairs is greater than 0.03 mm. Vellus hairs are produced by small, fully cycling hair follicles that reside in the dermis and do not extend to the subcutaneous tissue. These hairs are less than 0.03 mm in diameter, depigmented, short, and lacking a medullated hair shaft.
Terminal hair growth in women is under hormonal effect and, in some women, may be associated with increased circulating levels of androgens. However, in many women, androgen levels are normal, suggesting a hyperresponsiveness of the hair follicle to androgen stimulation. Other features of hyperandrogenism that support investigation by the practitioner into potential reversible causes of hyperandrogenism include oligorrhea or amenorrhea, infertility, acne, acanthosis nigricans, female pattern hair loss, virility, and clitoromegaly. Polycystic ovarian syndrome is the most common cause of hyperandrogenism; rapid onset of symptoms and testosterone levels greater than 200 ng/mL warrants an investigation for an androgen-secreting tumor. Patients with long-standing normal menses, normal fertility, and mild hirsutism may not need any systemic work-up for hirsutism. Sudden onset of generalized hypertrichosis lanuginosa should prompt work-up for malignancy; acquired hypertrichosis may be seen in porphyria cutanea tarda, variegate porphyria, and erythropoietic porphyria and with the use of multiple medications including cyclosporine, minoxidil, and phenytoin.
Techniques for removal of unwanted hair are discussed later. Hair can be reduced by temporary means that delay hair growth and have an effect for approximately 1 to 3 months, consistent with induction of the telogen phase of the hair cycle: the period of relative quiescence. Hair cycle duration is site dependent and varies from patient to patient. Permanent hair reduction techniques lead to a significant reduction in the number of terminal hairs after a given treatment. By definition, this reduction is stable for a period of time longer than the complete growth cycle of hair follicles at a given site. Table 1 may be useful when considering the timing of treating actively growing follicles (anagen) as well as considering efficacy of permanent hair reduction at a given site.