When he attends the Nasdaq-100 Open tennis tournament in Miami, Sorrel Resnik wears long sleeves, long pants, a hat and a towel to cover his hands. In addition, he uses SPF 45 sunscreen. He might look overdressed for March, he says, but he knows what the sun can do to unprotected skin.

As a voluntary clinical professor of dermatology and cutaneous surgery at the Leonard Miller School of Medicine at University of Miami, Resnik treats skin cancer patients every day. "I've taken off skin cancer on a 16-year-old already," says Resnik, who has practiced dermatology in Miami for 39 years.

He's been seeing promising developments, including the following for people with multiple skin cancer spots:

Photodynamic therapy:
A doctor applies a topical cream with aminolevulinic acid to the skin and lets it sit for about an hour. The medicine sticks to the cancer cells and is activated when the doctor shines an intense blue light on the skin. This method targets cancer cells without affecting healthy skin around them.

Topical creams:
Typical treatments over the years have involved applying fluorouracil cream to sun-exposed areas so the medicine can penetrate the skin's surface and bring cancerous cells to the top, where they can be cut out or scraped off. The creams have caused red patches, burning, inflammation, dryness, scaling and itching during the period of treatment, which leads some patients to avoid going out in public.
Recent advances have improved on those treatments for actinic keratoses, Resnik says. Lower concentrations of medication and new topical creams have cut down on skin irritation.

Originally the therapy caused severe pain and burning that lasted several days because doctors left it on the skin for 12 to 14 hours before applying the blue light. Doctors have refined the schedule and are waiting for the U.S. Food and Drug Administration to recognize the shorter application time, Resnik says.

Herbal supplement:
Polypodium leucotomos, which is sold under the names Heliocore and Kalawalla, has been used in Europe and South America and is becoming more recognized in the U.S. as a natural herb that treats psoriasis and dermatitis and prevents normal skin cells from becoming cancerous.

Resnik says studies by a Harvard physician and researcher known for his work on pigmentation and skin showed the herb slows down the effects of aging on the skin. Today, Resnik recommends that his patients, especially those who have had multiple skin cancers, take one tablet a day -- or on beach days, one in the morning and one in the afternoon.

Sun blocks:
Resnik used to recommend SPF 15 products, but now he says people should use a minimum of SPF 30 or, better yet, sunblocks such as zinc oxide and titanium dioxide, which don't need to be reapplied every couple of hours.