Skin Disorders

he skin is the body's largest and most visible organ. It reflects a person's general health and performs many important bodily functions. An average-sized person has 20 square feet of skin that serves as the body's front-line defense against injury and bacteria. The skin also regulates body temperature, acts as a sensory and excretory organ, and synthesizes vitamin D when exposed to ultraviolet light. A vast network of blood vessels in the skin provides oxygen and nutrients to sensory and motor nerves and also to skin appendages, including glands, nails, and hair.

Not surprisingly, this complex, exposed organ is vulnerable to many diseases. Each year, as many as seven million people seek medical treatment for newly diagnosed skin diseases. And almost everyone will experience some type of skin problem sooner or later. Skin disorders are usually noticeable and often disfiguring, causing both physical and psychological distress.

Some Other Skin Facts

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• The American Academy of Dermatology reports that one out of four people seeking medical advice about new skin problems is bedridden.
• Teenagers and young adults account for a significant number of dermatology (skin) patients. In highly urban areas, however, a surprisingly large proportion of patients are adults.
• Acne is the leading skin disease, occurring in 20 percent of all patients seeking treatment for skin disorders. Contact skin disorders, such as poison ivy and burns or rashes caused by industrial or household chemicals, are the second most common problem.
• Other common skin disorders include skin cancer, warts, fungal infections, and psoriasis.
• More than three million workdays are lost each year because of skin diseases.
• Chronic skin disease accounts for up to 50 percent of workers compensation claims in some states.
• Skin disease is the fourth largest cause of disability in the Armed Forces, affecting almost seven percent of military personnel.

The Skin's Architecture

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A CLOSER LOOK AT THE LARGEST ORGAN

Below the skin's deceptively smooth surface lies a veritable forest of support structures and glands, including nerves, muscles, capillaries, and the sebaceous glands implicated in acne. The epidermis, or top layer, acts as a protective barrier. As its cells are rubbed off and shed, cells in the dermis below are constantly dividing to provide replacements. When this renewal cycle gets out of control, the result is psoriasis.

The skin has three major layers--the epidermis, the dermis, and the subcutaneous tissue. The epidermis is the outermost layer of skin. Its main function is to produce the keratin that protects the body against harmful environmental substances and controls water loss. Cells in the epidermis also produce melanin, which gives the skin its color.

The next layer of the skin is the dermis. This layer contains a number of important substances such as collagen and reticulin, which prevent the skin from tearing; elastin, which makes the skin resilient; and jellylike substances that make the skin soft and compressible.

The third layer, subcutaneous tissue, is primarily made up of fat, which provides insulation, shock absorption, and calorie reserves. Both the dermis and the subcutaneous tissue contain sensory and motor nerves.

Among the most common causes of skin disorders are infections, overexposure to sunlight, follicle dysfunction, and hormonal imbalance. Parasites, external substances, cell dysfunction, genetic factors, stress, and aging also cause skin problems. Here are the most common skin disorders and their treatments:

Acne: The Leading Complaint

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Acne typically affects teenagers, occurring during a time of dramatic hormonal shifts and rapid growth. The blackheads, whiteheads, pimples, and boil-like lesions that appear on the face, back, chest, and shoulders are a source of embarrassment and may lead to permanent scarring.

Rising hormone levels during puberty cause the sebaceous glands to enlarge and produce more oil. No one knows why this process causes acne in some people but not in others. However, certain factors are known to contribute to the development of acne. They include oral contraceptives; certain medications, such as steroids, some hormones, iodides, bromides, and lithium; exposure to heavy oils, greases, or tars; trauma or irritation from tight clothing; cosmetics; and emotional stress.

Acne results when small kernels of sebum (oil), skin cells, and bacteria fill up hair follicles, causing blackheads and whiteheads to appear. The sebum ruptures the walls of the follicles, forming pimples and boil-like eruptions in nearby tissue. If the sebum is further altered by bacteria, it may cause even more irritation to the surrounding skin.

Acne is usually treated with an antibacterial agent such as benzoyl peroxide--either alone or in combination with tretinoin (Retin-A). Oral and topical antibiotics such as tetracycline, erythromycin, and topical clindamycin also help alleviate acne. Accutane (oral isotretinoin), inhibits the secretion of sebum, but has severe side effects and must be used cautiously.

Other acne remedies include injecting cortisone directly into the lesions, estrogen therapy for women, and exposure to ultraviolet light. Proper cleansing techniques also are often part of the therapeutic plan.

Rosacea and Rhinophyma

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Rosacea is a chronic skin disorder that produces flushing and dilation of the small blood vessels in the face. Tiny pimples also appear. As the disease progresses, small, thin, red lines (telangiectasia) may appear on the skin's surface. In advanced cases--and usually only in men--the nose becomes bulbous and red, the cheeks become puffy, and thick bumps develop on the lower half of the nose and adjacent cheek areas. We don't know what causes this condition, which is called rhinophyma, but the problem may be aggravated by stress, infection, vitamin deficiencies, and glandular upset.

Topical steroids as well as topical and oral antibacterial agents are helpful in the treatment of rosacea. Beta blockers can be used to reduce redness and swelling. The dilated blood vessels of telangiectasias can be closed off with a small needle, a laser, or surgery.

Rhinophyma is usually treated with surgery or dermabrasion. Most people with this disorder are advised to avoid alcohol, spicy foods, hot drinks, and smoking, and to stop using facial products that contain alcohol or other irritants.

Psoriasis: An Array of Treatment Options

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Psoriasis affects as many as eight million Americans. Though the cause is unknown, psoriasis results in an overproduction of skin cells. The surplus skin leads to thickening and scaling. The resulting silvery plaques generally appear on the scalp, elbows, knees, and lower back. The severity of psoriasis ranges from mild, undetected forms to rare cases in which the scales cover the entire body. Psoriasis may cause pitting of the fingernail surface, thickening and crumbling of the nail plate, and separation of the nail from the nail bed.

Genetic factors apparently cause a biochemical malfunction that triggers the psoriasis. Skin cells mature in three to four days-- much faster than the usual 28 to 30 days--resulting in a flaky buildup. Itching, occasional pain, and embarrassment are the chief complaints of psoriasis sufferers.

Treatment of psoriasis consists of removing the scales by softening them with certain preparations, then gently scrubbing the skin with a soft brush in an oatmeal or salt bath. Other treatments include exposure to ultraviolet type B light (UVB), coal tar preparations, steroid creams, methotrexate (an anticancer drug), anthralin, and PUVA (psoralen in conjunction with UVA exposure). Tegison, a synthetic vitamin A derivative, is sometimes used in conjunction with PUVA, UVB, and topical medications. Low-dosage antihistamines may also be prescribed.

Arthritic symptoms often accompany psoriasis. Aspirin and local heat usually relieve these symptoms. Severe cases may require nonsteroidal anti-inflammatory drugs. Psoriasis of the scalp often responds to the use of tar shampoo and steroid lotion. Psoriasis of the fingernail cannot be treated, but usually clears up when the skin lesions subside.

Dermatitis: Many Forms, Many Remedies

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Dermatitis is the general term for any inflammation of the skin. There are many types of dermatitis and many different causes.

Atopic eczema affects about three percent of the United States population and often occurs as an allergic reaction to wool, silk, fur, ointment, detergent, perfume, wheat, milk, or eggs. It produces an intensely itchy rash that blisters, oozes, and crusts. In infants, it appears primarily on the face and scalp. When it occurs in adolescents and young adults, it is usually found in the large folds of the hands and feet; elbow bends and backs of knees; and the face, neck, and upper chest.

Doctors usually treat atopic eczema with topical corticosteroids and petrolatum, sedatives, and antihistamines. Oral antibiotics may be prescribed for a secondary infection; ultraviolet light therapy has been helpful in treating severe cases. Patients are instructed to eliminate or avoid allergens, irritants, extreme temperatures, stress, and other possible aggravating factors.

Seborrheic dermatitis is another common skin disorder. This chronic condition causes red skin covered by yellowish, greasy-appearing scales and usually occurs on the scalp (where it's known as dandruff), sides of the nose, eyebrows, eyelids, skin behind the ears, and the middle of the chest. Treatment with low-strength topical cortisone preparations usually provides relief. Scalp treatments include frequent shampoos with preparations containing such chemicals as tar, zinc pyrithione, selenium sulfide, sulfur, and/or salicylic acid. Seborrheic dermatitis may be caused or perpetuated by a yeast organism, and antiyeast creams have been used with good results by some people.

Other forms of dermatitis include contact dermatitis, localized neurodermatitis, stasis dermatitis, exfoliative dermatitis, and allergic contact dermatitis (poison ivy, oak, and sumac).

Infections: Common and Surprisingly Stubborn

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Athlete's foot may affect as many as 90 percent of Americans. This fungal infection shows up as sores between the toes, or as a blistering rash on the foot. Another type of athlete's foot manifests itself as a very mild inflammation and dry scaling of the entire sole of the foot, along with infection of the toenails. Treatment consists of dressings of tap water or a weak salt solution. Oral antibiotics and topical and oral antifungal medicines are also used. Other fungal infections of the skin include tinea versicolor and dermatophytosis (ringworm).

Other infection-related skin diseases include herpes and warts--both of which are viral infections; impetigo; folliculitis, furunculosis, carbunculosis, and staphylococcal scalded skin syndrome-- all bacterial infections; scabies--caused by the itch mite; cutaneous larva migrans--a reaction to infestation by hookworms and roundworms; and pediculosis--caused by parasitic forms of lice.

Also common are such skin conditions as hives, which are treated with antihistamines and the removal of the offending agent; and vitiligo, a condition in which pigment cells are destroyed, which is treated with repigmentation drugs activated by ultraviolet light.

Skin Cancer: The Three Major Types

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Basal cell carcinoma is the most common form of skin cancer and affects some 400,000 people each year. The tumors appear as small, fleshy, translucent bumps or nodules on the head, neck, hands, or occasionally, on the trunk of the body. These tumors don't grow quickly and don't metastasize (spread to other organs). If left untreated, however, the tumors begin to bleed, crust over, and then repeat the cycle. If treatment is further delayed, basal cell carcinoma can invade the skin and spread, causing significant damage as it extends.

Squamous cell carcinoma tumors appear as nodules that ulcerate in the center, or as red, scaly patches on the rim of the ear, face, lips, and mouth. The tumors eventually enlarge into sizable masses and can spread via the blood and lymph systems.

A malignant melanoma is the most virulent of all skin cancers. If untreated, it can be fatal; and in the U.S., the increase in new cases tops all other forms of skin cancer.

Malignant melanoma results from the uncontrolled growth of pigment-producing tanning cells. It resembles an oversized, asymmetrical mole and is characterized by an irregular border and unusual pigmentation. Any mole larger than a pencil eraser that has these characteristics is cause for concern and should be checked.

As with all skin cancers, malignant melanoma is thought to be linked with excessive exposure to the sun. It also tends to run in families. If a relative has had it, extra caution is advisable.

Malignant melanoma may appear suddenly without warning or may begin near a mole or another dark spot on the skin. Additional warning signs include changes in the surface of a mole, oozing, scaliness, bleeding or the appearance of a bump or nodule; spread of pigment from the border of a mole into the surrounding skin; and changes in sensation, such as pain, tenderness, or itching. If detected early enough, melanoma can usually be cured by surgical removal.

Several options are available for treating basal cell and squamous cell carcinomas. Treatment may involve surgical removal; electrodesiccation (destroying cancerous tissue with a high-frequency current transmitted through a needle electrode); cryosurgery (using cold liquid nitrogen to destroy the cancerous tissue); radiation therapy; and topical chemotherapy.

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