Is beauty but skin deep? From acne to wrinkles, Skin Sense! is an invaluable resource for anyone concerned about the state of his or her skin. Authored by an internationally recognized, board certified dermatologist, Skin Sense! explores our outermost layer in both health and disease including such diverse topics as: Complexion do's and don'ts Changing moles, indoor tanning, and the skin cancer epidemic Up-to-date management strategies for acne, psoriasis and eczema Contagious disorders such as scabies, herpes, MRSA and impetigo Hot anti-aging therapies: Botox, dermal fillers, microdermabrasion, laser.

Skin Sense!

A Dermatologist's Guide to Skin and Facial CareBy Stephen M. Schleicher

iUniverse, Inc.

Copyright © 2009 Stephen M. Schleicher, MD
All right reserved.
ISBN: 978-1-4401-7427-8

Contents

INTRODUCTION.............................................VIINORMAL SKIN..............................................1NUTRITION AND THE SKIN...................................4DRY SKIN.................................................13THE ACNE PROBLEM.........................................15ROSACEA AND PERIORAL DERMATITIS..........................24PERSPIRATION.............................................27ITCHY SKIN...............................................29HAIR, SCALP, AND NAILS...................................31CELLULITE AND STRETCH MARKS..............................41DILATED BLOOD VESSELS....................................43AGING AND THE SKIN.......................................45THE SUN AND SKIN.........................................52BENIGN SKIN GROWTHS......................................60PREMALIGNANT GROWTHS AND SKIN CANCER.....................63COMMON SKIN INFECTIONS...................................67PSORIASIS................................................84ECZEMA/ATOPIC DERMATITIS.................................88ISORDERS OF PIGMENT......................................91HIVES....................................................94IRRITANT AND CONTACT DERMATITIS..........................96DIABETES AND THE SKIN....................................101THYROID AND THE SKIN.....................................103AUTOIMMUNE DISEASES......................................104SPORTS AND THE SKIN......................................106SKIN OF COLOR............................................108SKIN FIRST AID...........................................110CONCLUSION...............................................117

Chapter One

NORMAL SKIN

Our skin, the cutaneous organ, is composed of three distinct layers: the epidermis, the dermis, and subcutaneous (or fat) tissue. The following brief descriptions of each layer will greatly aid you in understanding both healthy and diseased skin.

The epidermis constitutes the outermost layer and is the only part of the skin that is visible to us. From a cosmetic standpoint, the epidermis is naturally of paramount importance.

The epidermis is the thinnest of all layers and over much of our body it is only one-sixteenth of an inch thick, about as thick as this page. The epidermis is thickest on the palms and soles, where it may reach nearly one-eighth of an inch.

The epidermis is composed of both living and dead cells. New cells are produced in the lowest portion, the basal layer. These cells migrate upward to the surface to become the cornified layer. Here the cells form a resilient, waterproof material known as keratin. Dead surface cells are continuously shed as miniscule flakes (scales) and are immediately replaced by living cells from the layers below. Some twenty-eight days are required for a new cell produced in the basal layer to finally reach the outer cornified zone; in other words, complete replacement of the epidermis takes nearly one month.

The epidermis is devoid of blood vessels. This alone gives some indication of the thinness of this layer, for we all have experienced bleeding following a superficial nick or cut. Thus even the most trivial of wounds easily traverse the thin epidermis to enter the next layer, the dermis.

The dermis is some forty times thicker than the epidermis. Besides harboring blood vessels, it also contains nerves, sweat glands, and sebaceous oil glands. The dermis feeds the cells of the basal layer and consequently regulates the growth of the entire epidermis. Tautness of the skin is in large part due to components such as collagen and elastin fibers that reside in the dermis.

The dermis rests on a thick pad of fat called the subcutaneous layer. This layer, like the epidermis, varies in thickness depending on body location. It is practically nonexistent within the eyelid and, as you might guess, becomes thickest around the waist (too thick in some cases!). The subcutaneous tissue serves as a thermal insulator and shock absorber.

Unhealthy skin may result from a disease process that affects any or all of the three layers. For example, dry skin involves changes in the epidermis; acne is a disorder of sebaceous glands located in the dermis; and cellulite arises from alterations in the subcutaneous tissue. You'll find more on these conditions in upcoming chapters.

Male and Female Skin

So, is male skin from Mars and female skin from Venus? Hopefully, we are all Earthlings, but differences in the sexes certainly carry over to our skin as well. Male skin is indeed thicker than female skin. Increased collagen and elastin fibers in men contribute to firmness and are a main reason why men tend to age with fewer deep-set wrinkles and fine lines than women. Another reason for aging disparity is the fact that male skin has a greater number of coarse hair follicles. Over time, exposure to solar radiation breaks down dermal collagen and contributes mightily to wrinkle formation, but facial hair (the male beard) acts as a physical screen to ultraviolet light.

Male skin has more active oil and sweat-gland activity than female skin; thus men have less need to moisturize. Bacteria living on the skin surface degrade sweat, leading to the characteristic musty aroma of the male armpit and the enhanced need for deodorants (at least when out in public!).

The placement of fat is to some degree sex-related and varies in males and females. The distribution in women gives rise to the more rounded contours associated with the feminine figure and in large part contributes to culturally defined "sexiness."

Black and White Skin

Pigment cells within the skin are called melanocytes, and the actual pigment is known as melanin. Melanin production varies among the various cultural groups, including Africans, Asians, and Caucasians. Interestingly, black skin does not contain more melanocytes, but it does tend to contain more melanin. The melanin granules are larger and darker.

Variations in human skin color have evolved over the ages. Black skin is the most resistant to ultraviolet light and is ideally suited to withstand chronic sun exposure. Indeed, unprotected white or pale skin is a sitting duck for skin cancer.

A redeeming feature of sunlight is that it induces production of vitamin D, which is extremely important for our health and well-being. Thus melanin serves as a double-edged sword. By blocking solar radiation, melanin protects against skin cancer, but it also prohibits vitamin D production. One can postulate that as humans migrated from sunnier climates to colder ones, skin lightening was a positive adaptation to a changing environment. The need for melanin to prevent skin cancer lessened with decreased sun exposure, and decreased amounts of melanin actually enhanced vitamin D production by skin cells.

NUTRITION AND THE SKIN

Three main food types are essential in the everyday maintenance of our body. These are carbohydrates, proteins, and fats, all of which contribute to healthy skin.

Despite occasional pitches to the contrary, a "superskin" diet has yet to be developed. Perhaps one day what we eat will indeed serve as a fountain of youth that thwarts the aging process. For now one would do best to follow the sound nutritional principles that medical doctors advocate for...