Barrido de potencial

The primary treatment o f excessive hair growth will depend upon whether a cause can be diagnosed. Endocrine imbalance can be corrected by either medical or surgical intervention. However, where an actual cause is not found, or the corrective procedure

Chapter 1 - General Introduction

is not successful enough, then other methods o f hair eradication less systemically disturbing may be required. Current treatments available for hirsutism are listed below.

Chemical Physical

Hormonal suppression Shaving

Dexamethasone Topical creams

Oral Contraceptive Bleaching

Gonadotropin releasing hormone agonist Plucking and waxing

Antiandrogens Electrolysis Spironolactone Laser Cyproterone acetate Flutamide Miscellaneous Ketoconazole

Individuals usually request treatment for excess terminal hair growth as they generally feel that they do not conform to the values placed on them by society as a whole. As mentioned earlier, between 5 and 10% o f the female Caucasian population have been described as hirsute and treating only a fraction o f this number would place quite a sizeable demand upon health care resources. Consequently the management o f the majority o f hirsute individuals is presently being performed mainly within the private sector. In addition, the lack of an effective method of producing permanent dépilation has resulted in a multimillion pound business for the cosmetic industry which constantly advertises the benefits of having smooth, hairless skin.

Although dépilation could be seen as being a purely cosmetic practice, the continuing evolution of reconstructive surgery has realised a potential for finding a safe, simple and effective method for removing unwanted hair from skin. The ability to transplant a flap o f hair bearing skin to a non-hair bearing site and then to rid that flap of hair

would produce a much more agreeable result for the patient concerned and vastly increase the quantity of available skin for reconstructive purposes. In addition, the use o f skin to replace a damaged or diseased tubular structure within the body, such as oesophagus (Kuriloff, et ah, 1988) or urethra (Finkelstein and Blatstein, 1991), has been performed in the past but generally resulted in a poor outcome. In part this is due to the obstruction to flow within the tube produced by the presence and growth of hairs. This has been seen to occur particularly in the urethra where calculi have formed on the hairs ultimately preventing the flow o f urine. Therefore, the development o f a successful permanent depilator with the requisite abilities could have far reaching effects within medical practice as a whole.

Currently, the methods used for the treatment of excess hair can be categorised into either physical or chemical (see previous page). Chemical methods employed for the treatment of hirsutism include drugs which suppress the body's usual hormone production. Such examples would include the oral contraceptive pill, which attempts to regulate sex hormone production by placing an external, constant control on the hormone cycle so suppressing the bodies natural production. A more direct approach and one that can result in greater side effects includes the use of antiandrogens [Barth, 1991 #339] (such as flutamide and cyproterone acetate) which directly inhibit either the production or action of androgenic hormones. Other anti-androgenic drugs include spironolactone, but the side effects induced by this medication can be much greater ranging from headaches to blood pressure fluctuations. Therefore its use is only recommended under extreme circumstances.

Physical methods used for the reduction in unwanted hair growth vary in technique and success with both electrolysis and now laser being the only two stated to have a permanent effect. Shaving and bleaching per se do not reduce hair growth but merely make it less conspicuous. Shaving has been shown not to produce thicker hairs or ones that grow more rapidly (Natow, 1986). Topical creams act by dissolving the hair shaft at the disulphide bonds and is a temporary method. Side effects can include contact dermatitis, which may be aggressive on sensitive skin types. Plucking is also a temporary depilatory method and is best used in areas where the hair density is low.

Chapter 1 - General Introduction

The procedure can be painful and the follicle may become infected upon regrowth. Waxing requires the hairs to be o f a certain length so that they can be “gripped” by the wax as it is removed. The technique is again temporary but relatively cheap and patients may not require further treatment for upto 6 weeks afterwards.

Electrolysis is a depilatory technique described as permanent removing the hair using an electrode inserted into the ostium or canal of the follicle. True electrolysis, first used over 100 years ago, involves the production o f sodium hydroxide from sodium chloride and water which are present within the follicle. This occurs when an electric current is passed through the electrode. The sodium hydroxide then destroys the viable follicular tissues and hopefully prevents the hair regrowing. Thermolysis is the method most often used today and involves heat production to destroy the hair cell components via radiowaves (cf. surgical diathermy equipment). A third technique also exists which incorporates both of the previous two methods and is termed The Blend. This has been stated to be the most effective format for permanent dépilation although a specific comparison o f the results has not been performed (Richards and Meharg, 1995). Overall the hair regrowth rates vary between 15 and 50% and complications can include infection, hypo and hyperpigmentation and permanent scarring with keloid formation (Wagner, et al., 1985). Diphtherial endocarditis (Cookson and Harris, 1981) and the spreading o f flat warts (Petrozzi, 1980) have also been reported. It is also a time consuming procedure because only one hair follicle can be treated at once.

From the text above, it becomes apparent that until recently no safe, simple or effective method was available to produce permanent dépilation. Exactly who first described laser-assisted hair removal is not completely clear, but its discovery over 10 years ago has potentially revolutionised the treatment of unwanted hair. The types of laser used have varied, with a carbon dioxide laser stated to have achieved partial depilatory success on an oesophageal reconstruction using a delto-pectoral flap and a Wooky-type cervical skin flap (Kuriloff, et al., 1988) and an NdYAG laser achieving partial depilatory success upon urethras reconstructed using hair-bearing skin from the scrotum (Finkelstein and Blatstein, 1991). It is presently thought that the ruby laser

should be the most effective at depilating skin but to explain why, it becomes necessary to discuss how lasers actually work.

1.5 LASERS