Skin savers

Most runners are fine with the fact that a career as a foot model is not in the cards for them. Calluses and hard heels are just part of the deal in doing what you love. But when it comes to some of the other, uglier ailments, like chafing or a black big toenail, there are ways to steer clear, said Brian B. Adams, M.D., an associate professor of dermatology and director of the Sports Dermatology Clinic at the University of Cincinnati. Learn how to prevent six common conditions -- and what to do if you already have them.

Blister

On your foot, the fluid-filled sore is your body's response to too much friction.

Prevent it: Moisture is the big culprit, so keep feet dry by wearing socks that wick sweat away, such as Coolmax. Spraying on antiperspirant (any brand will work) also helps. When running outside, avoid puddles. And if you pour water over your head to cool off, lean forward so the water doesn't go into your shoes, said Charles E. Crutchfield III, M.D., a clinical associate professor of dermatology at the University of Minnesota Medical School in Minneapolis.

Treat it: Using a sterile needle, poke a hole in the edge of the blister to drain the fluid. "Be sure to keep the 'roof' of the blister intact -- it's the best dressing for the blister," Adams said. Then apply petroleum jelly or an antibiotic ointment and cover with either a regular bandage or a thicker moleskin one, which offers extra cushioning.

Chafing

Mile after mile, ill-fitting clothes can rub you raw under your arms or on your inner thighs.

Prevent it: Don't wear clothes that are either oversized or too tight. Also, avoid tops and bottoms made of thick cotton, which swells when wet from sweat. For long runs or if you already have chafing, Crutchfield recommends applying lubricants such as petroleum jelly, Body Glide or runner's lube to your inner thighs and underarms.

Treat it: The red lesions will eventually heal on their own, but you can apply an antibacterial ointment or petroleum jelly to relieve soreness.

Runner's nipples

Chafing of the nipples is so common that the condition has its own name. For women, the main cause is damp cotton jogging bras.

Prevent it: Petroleum jelly is your best friend. Apply it to your nipples before getting dressed. Make sure your bra fits well and is made of moisture-wicking material, Adams said. You may also want to stick to performance-wear tops.

Treat it: As with general chafing, there isn't much you can do other than soothe skin with an antibacterial ointment or petroleum jelly.

Sunburn

You know better than to go out without slathering on sunscreen, but on hot and humid days or during long runs, you can sweat off all your protection.

Prevent it: Put on sunscreen about half an hour before going outside so your skin has ample time to absorb it. It should be waterproof and have an SPF of at least 35. If you're not a fan of applying sunscreen to your upper face because it tends to run into -- and sting -- your eyes, opt for a baseball cap and sunglasses for extra protection. For long runs or on broiling days, bring a small tube of sunscreen with you so you can reapply, Crutchfield said. (For more tips on how to beat the heat, click here.)

Treat it: Keep skin cool and moist by covering the burn with chilled aloe vera gel every four hours. An over-the-counter hydrocortisone cream can help with itching, inflammation and discomfort; apply it twice daily for five days. To relieve pain, take two aspirin every eight hours for the first two to three days.

Athlete's foot

Walking barefoot in locker rooms and gym showers, you can pick up a foot fungus that will dine on your skin, creating red, itchy sores.

Prevent it: Nix the whole gross affair by always wearing flip-flops in public showers and steam rooms. When running, wear moisture-wicking socks -- no athlete should ever wear cotton socks because they keep feet damp, Adams said. If athlete's foot is a recurring problem, try an antifungal powder.

Treat it: Apply an over-the-counter topical antifungal cream such as Lamisil. If irritation persists after several weeks, see your dermatologist. You may need a prescription for an oral medication.

Jogger's toe

Repeated contact between your longest toe and the toe box of your shoe injures the bed of the toenail. The trapped blood then dries and makes the nail look black.

Prevent it: Your toes need their space! When buying kicks, make sure you can wiggle them. "If you can't, you need a bigger toe box," Adams said. Also, cut toenails straight across, rather than curved, so that the whole top of the nail, and not a round tip, absorbs the impact from running.

Treat it: Your only option is to leave the damaged nail alone. Eventually, a new one will replace it.