Even though we often don’t think of it in these terms, our skin is our biggest organ. Skin is made up of two main layers: the outer epidermis and inner dermis. The epidermis is made up of flat, scale-like cells called squamous, according to the American Academy of Dermatology (AAD). Under that are round cells known as basal cells. Also deep in the skin are melanocytes, cells that produce melanin, which gives our skin its color.

Because the skin is exposed to the outside world, a host of problems can afflict it. Dermatologists say everyone should have a full-body skin evaluation. Then, depending on the patient’s family history of skin cancer, personal health history and risk factors, the doctor can advise how often to be checked after that.

Don’t forget the sunscreen

Knowledge of proper sunscreen use is a must. “Everyone should know to avoid the peak hours, 10 a.m. to 2 p.m.,” says Suzan Obagi, M.D., dermatology professor at the University of Pittsburgh. “People should apply a sunblock on their face every day of the year,” she says. “Use one that protects against ultraviolet A and B. There is a new product that was just approved by the FDA that also has UVA protection.” UVA exposure is a big contributor to many skin problems, she adds.

Because people get the majority of their exposure to the sun before they turn 21, dermatologists say, parents must be diligent about teaching children the importance of using sunscreen. “Reapply it every time you swim or sweat,” says Obagi. “Most damage is done when a person is six or seven years old. Most people think you get too much in your 20s, but it’s much earlier than that.”

Help for acne

Acne is a disorder driven by hormones and hormonal changes, explains Charles Crutchfield III, M.D., a dermatologist in St. Paul, Minnesota. It often begins in a person’s teen years, and there are misconceptions about acne, he says. “People think it’s about dirty skin and what you eat,” he says. “Certain people have triggers, so if certain foods trigger it, avoid them. But it’s not simply a teenage problem. Often, it goes on until a person is in their 30s.”

Obagi believes that growth hormone in foods, especially dairy, can spur acne. “One thing people with bad acne should consider is whether they are sensitive to dairy products,” she says. “Take a break from dairy products for six months and see whether it helps.”

Obagi also believes genetics play a role. “You can’t change your genes,” she says. “When you see (acne affecting) your children, jump on it early with a dermatologist so we can treat it before it starts scarring.”

Both Crutchfield and Obagi say many over-the-counter medications can be quite good for treating acne. If they are not effective, a dermatologist can prescribe medications to combat it. “No one should suffer with acne these days because we have so many treatments,” says Crutchfield. “I have about 10 different things to treat acne and the key is to find the right combination for each person. There are oral, laser, topical and over-the-counter medications that can be used in a combination.”

Dermatitis

Dermatitis is an inflammation of the skin. It is marked by redness, scaling and irritation. “Lots of different things can cause it,” says Crutchfield. “Allergy to nickel can often bring it on. Lots of jewelry has nickel in it, which can cause a rash.”

Crutchfield says that despite the industry’s constant marketing of new products, skin care is simple. For dermatitis and many other dermatological problems, he recommends gentle cleansing, proper moisturizing, protection and correction.

Soap should have little or no detergent or fragrance and people should us a moisturizer every day, especially after bathing, to seal in the water for hydrated skin. Crutchfield advises using a sunscreen of 15 SPF or higher with ultraviolet A or B protection. Correction for skin damage ranges from mild topical products to prescriptions that are much stronger.

Psoriasis

Psoriasis is an inflammatory condition of the skin that stems from some abnormality in the immune system, causing the skin to grow too fast, says Crutchfield. “If you have it, use the four principles (gentle cleansing, moisturizing, protecting and correcting). It affects five percent of all people,” he adds.

Psoriasis often shows up around the knees and elbows and can be painful. Treatment includes topical treatments, phototherapy, pills and biologic agents that are injectable, says Crutchfield.

Moles

Almost everyone has moles. The average number for adults is between 20 and 40, according to the AAD. “Moles are collections of a special population of skin cells called melanocytes,” says Crutchfield. “They produce color when you get a suntan. Moles are made up of groups of melanocytes.”

Crutchfield says a mole that changes in any way — size, color, shape or elevation — or any moles that bleed and don’t heal in three weeks without provocation should be checked by a dermatologist as soon as possible. “Only about a quarter are really skin cancer,” he says. “But don’t wait; don’t watch it. Have someone who knows about it check it out.”

Obagi notes that moles can change into melanoma, which she says is one of the deadliest cancers known. “The incidence of melanoma is skyrocketing because of our increased exposure to the sun,” she says.

Actinic keratosis

Obagi describes actinic keratosis as red, raw, scaly patches that can indicate precancerous changes. “Fair-skinned people see them more than darker-skinned people, but that doesn’t mean people with darker skin are immune. They are just better equipped to deal with it,” she says.

This problem happens because of cumulative sun damage, which can cause changes in the DNA. “Most won’t turn into skin cancers, but when they have numerous lesions, there is a greater chance,” says Obagi. She treats the problem by causing the skin in the area to peel. She applies liquid nitrogen or chemotherapeutic cream to effect changes.

These are destructive changes that help the skin go back to normal,” Obagi explains.

Warts

Warts are one of the most resilient viruses known to man, says Obagi. “The virus can live on the floor, shower, shoes and carpets,” she says. “The reason one person gets it and another doesn’t is the difference in their immune systems. Some people’s systems don’t protect against it.”

Warts are not dangerous, but are more of a cosmetic issue, Obagi says. “There are different treatments for them,” she explains. Over-the-counter liquids cause the wart to be destroyed over time. Or a doctor can use a laser, cutting or freezing to remove the wart.

Someone with more than just a few warts will possibly need prescription agents that stimulate interferon, which causes an immune response to get rid of the wart, she says.

Another remedy, according to Obagi: Simply cover the wart with duct tape. “It helps, believe it or not, because warts don’t like to be covered up.”

Tim Martin is a journalist living in Columbus, Ohio who specializes in medical reporting