INTRODUCTION
The “Menaissance†era is upon us. Drivers of male patients to seek aesthetic interventions include societal pressures to appear rested and refreshed, especially in an increasingly competitive job market. Irrespective of motive, the male aesthetic patient has arrived. Lasers and light sources could potentially serve as a “gateway†procedure, whereby removal of an unsightly cutaneous lesion could open the door to other treatments such as injectables. There is a paucity of literature exploring the effects of lasers and lights on men in particular. After a discussion of male cutaneous physiology we review these existing publications, and conclude with observations from our clinical practices.
Male Cutaneous Milieu
Skin Optics
When a laser beam interacts with the skin there are four possible outcomes: it can be reflected, absorbed, scattered, or transmitted.1 Laser scattering is dependent on the laser’s wavelength and affects the depth of penetration of radiation into the skin. In the dermis, scattering depends on the size of structures such as collagen that impede the photons path to the target chromophore. Absorbed photons can produce thermal, mechanical, or chemical changes to the chromophore. Skin structures (eg, terminal versus vellus hairs) that contain increased concentration of chromophore result in increased absorption. The laser-skin interaction, therefore, depends on cutaneous physiology. Since gender is one of the most significant factors that determine cutaneous physiology, it plays a critical role in the laser surgery.
Cutaneous Physiology
Skin metabolizes and responds to sex hormones2. The quantitative gender differences of sex steroids lead to gender differences in cutaneous physiology. Male skin is thicker at all ages, 3 but the difference varies with anatomical region.4 Mirroring the gradual decrease in testosterone, male skin thickness decreases linearly with age.5 Gender differences in skin thickness are thought to be due to differences in dermal collagen content and size. The total hydroxyl-proline content in men is greater than women at all ages.6 In mouse models, electron microscopy showed statistically significant differences in the collagen fibril diameter between men and women.7
Male cutaneous appendages show greater activity with men having higher sebum and sweat production. There are significant differences in hair distribution because the growth of sexual hair is dependent on androgens. Androgens convert non-pigmented vellus hairs into pigmented, terminal hairs. Androgen-dependent areas include the chin, upper lip, chest, abdomen, and back. The increase in terminal hairs contributes to the male facial vascular pattern.8 A doppler flow perfusion study documented increased facial vascular perfusion in men.9 A dense plexus of arteries support the hair follicle. Large diameter hair follicles require more capillaries to support their
