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The FDA is warning consumers not to buy in to the idea that a pill can protect your skin from the sun.

In a statement issued May 22, FDA officials said they've found companies selling pills that are labeled as dietary supplements and that claim to protect skin from the sun.

Rates of the two most common skin cancers have more than doubled over the past decade. Here's how to protect yourself.

When it comes to skin cancer, there's good news and bad news. First, the bad news. A report published in the June 2017 Mayo Clinic Proceedings found that cases of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) skin cancers have risen 263% and 145%, respectively, over the past decade.

The good news? BCC and SCC are rarely life-threatening and they're usually easy to treat if they're caught early. Plus, there are simple ways to prevent them.

In the journals

A prescription cream called 5-fluorouracil (5-FU, sold as Adrucil and other brands) may help people reduce their risk for squamous cell carcinoma (SCC), according to a study published in the Jan. 3, 2017, JAMA Dermatology. SCC, the second most common cancer in the United States, strikes twice as many men as women.

Researchers recruited 932 people, 98% of whom were men, with an average age of 71. Each had experienced at least two skin cancers 鈥� SCC, basal cell carcinoma (BCC, the most common skin cancer), or both 鈥� on their face or ears within the past five years. They were randomly assigned to receive either the 5-FU cream or a placebo cream. Everyone applied a thin layer twice a day to their face and ears for up to four weeks. Over the course of a year, the 5-FU group had a 75% lower incidence of SCC compared with the placebo group. They also had a 11% lower incidence of BCC, but this difference was not statistically significant. It's not known why 5-FU helped prevent SCC but not BCC, according to the researchers.

In the journals

听Image: 漏 Manuel-F-O/Thinkstock

While it's important to have any suspicious mole checked for possible skin cancer, a study published online Aug. 29, 2017, by the Journal of the American Academy of Dermatology suggests most melanomas 鈥� the deadliest skin cancer 鈥� appear as new spots on the skin. The researchers reviewed 38 studies involving 20,126 cases of melanoma and found that 29% of diagnosed melanomas came from an existing mole, while 71% appeared as new spots. Moreover, they discovered that melanomas that grew from moles were thinner and thus less aggressive than other melanomas. In fact, people whose melanoma was associated with a mole had a better prognosis than others.

The study's authors stressed the importance of looking for any new spots on the skin as well as checking moles for changes, like itching or bleeding, and to see a dermatologist if needed. The American Academy of Dermatology encourages everyone to perform regular skin self-exams, and to ask a partner to check hard-to-see areas like the back. You can learn how to do a skin self-exam, and much more, at .

Research we're watching

听Image: 漏 ChesiireCat/Thinkstock

To catch skin cancer early, be on the lookout for new spots on your skin. A recent study found that more often than not, melanoma occurs as a new spot on your body 鈥� not as changes in an existing mole. The study, published online August 29 by the Journal of the American Academy of Dermatology, found that only 29% of melanomas came from an existing mole on the body that changed. In 71% of cases, melanoma occurred in a new lesion that popped up in a new place on the skin. In addition, the study authors noted that melanomas that do occur in existing moles tend to be thinner than melanomas in new lesions.

In addition to looking for new and unusual spots on your skin, remember your ABCDs to spot the signs of melanoma:

Research we're watching

You probably know to have your skin checked frequently for the signs of melanoma. But you should also be looking out for another, more common type of skin cancer 鈥� squamous cell carcinoma. This potentially lethal skin cancer can show up on your skin as a white or pink bump, a non-healing sore, or even a scaly patch. According to the American Academy of Dermatology, cases of squamous cell carcinoma are on the rise, with some 700,000 new diagnoses each year.

"While other skin cancers may be more lethal, they're less common," writes Dr. M. Laurin Council, an assistant professor of dermatology at Washington University in St. Louis. "Squamous cell carcinoma is highly treatable when detected early, so it's important for people to know the signs of this disease and keep a close eye on their skin."

On call

Q. I have a history of skin cancer, so I am careful with my sunscreen application. I recently heard that I should avoid spray sunscreens. Is that true?

A. Sunscreen use is highly recommended to help prevent skin damage from sun exposure. Spray sunscreens are popular because they are easy to apply and help cover hard-to-reach areas like the back and shoulders. However, they do raise a few concerns. One is the chance of inhaling some of the sunscreen ingredients or its propellant. The health risk from this is uncertain, but it may trigger asthma in susceptible men. The FDA has not specifically determined the health risks of inhaling sunscreen sprays, but recently advised not to use them near your face.

Ask the doctors

Image: 漏 Click_and_Photo/Thinkstock
Q. I like gel manicures because the polish doesn't chip easily, but I've heard that they may cause cancer. Is this true?

A. The gel polish itself hasn't been associated with an increased risk of cancer. However, lamps and light boxes, which are used to seal the polish during professional manicures, have raised concern. That's because many emit fairly high levels of UVA radiation, which plays a major role in the development of cancer. The level of risk depends on the frequency of manicures. A 2014 study in JAMA Dermatology indicated that the level of UVA exposure associated with a gel manicure every two weeks probably isn't high enough to increase the risk of skin cancer significantly.

Research we're watching

Image: 漏 Igor Gratzer/Thinkstock
In Hans Christian Andersen's classic fairy tale, the ugly duckling stands out from the flock because he's destined to become a swan. In dermatology, the "ugly duckling" is a mole that doesn't look like the rest of the moles on a person's body, and is often suspected to be a melanoma.

A team of French researchers decided to test whether finding an ugly duckling among all of a patient's moles is as effective a way of identifying melanoma as applying diagnostic criteria 鈥� like size, shape, color, and irregularity 鈥� to each mole separately. For the study, nine dermatologists studied images of 2,089 individual moles from 80 people. The images were presented to the dermatologists two different ways on two different days. On one day, they evaluated each image separately; on another, they looked for the ugly ducklings among the complete set of moles from each patient. They were able to flag the melanomas accurately both times. However, they were able to decrease the number of moles biopsied when they used the ugly duckling system.

Dr. Robert S. Stern, chair of the Department of Dermatology at Harvard-affiliated Beth Israel Deaconess Medical Center , calls them "solar-phobes": people so concerned about getting skin cancer that they stay inside or cover every bit of skin. "They cover up like they were going out into the Arabian Desert ," he says. The marketing of ultrablocking sunscreens and special sun-protective clothing plays into these fears.

There's no getting around the fact that sunlight is hard on your skin. Age gets blamed for wrinkles and rough, dry skin. But the real culprit is a combination of age and sun that dermatologists call photoaging. The short UVB wavelengths that cause sunburn can also damage DNA and suppress the skin's immune system. The longer, more penetrating UVA wavelengths may create highly reactive oxygen molecules capable of damaging skin cell membranes and the DNA inside.