It all began with a white prom dress.
Brittany Lietz, then 17, bought the dress but decided that she would look prettier in it if her naturally pale skin were a little darker.
Lietz, from Edgewater, Md., made an appointment at a local tanning salon for an eight-minute session. Over the next three years, her tanning habit grew into an addiction, a daily ritual that eventually resulted in melanoma, the deadliest skin cancer.
"My body almost felt the need to go tanning to have that euphoria feeling of calmness," said Lietz, now 23. "I was so naïve."
Lietz was not alone with her diagnosis. In a recent researcher letter in the Journal of Investigative Dermatology, doctors reported that the incidence of melanoma increased 50 percent in a representative population aged 15-39 between 1980 and 2004, from 9.4 to 14 cases per 100,000 women.
And young women tend to have more sun-seeking behaviors than men, particularly indoor and outdoor tanning. The increase in melanomas can be a serious consequence.
"It's unlikely that a change in incidents of this magnitude within a relatively short span of years would be due to some kind of genetic factor," said Dr. Mark Purdue, a researcher in the Division of Cancer Epidemiology and Genetics at the National Cancer Institute in Bethesda, Md., and author of the letter. "It is more likely that it's some kind of environmental factor."
Melanomas, which form when pigment cells in the skin become cancerous, account for less than 5 percent of skin cancer cases but they are responsible for over 70 percent of skin cancer deaths, according to the American Cancer Society.
Kelli Pedroia, wife of Red Sox player Dustin Pedroia, also struggled with melanoma as a result of sun damage. Although she was diagnosed at age 18, Pedroia failed to grasp the gravity of her condition and continued to sunbathe and frequent tanning salons.
"At 18, I did not get it," she said. "I thought, it happened once, it will never happen to me again." Pedroia, now 24, added, "For me, it is 100 percent addictive, you feel better after you go tanning."
But for some, tanning can go beyond addiction. Body image experts say people who have a distorted perception of their appearance, a condition called body dysmorphic disorder, often are concerned with their skin.
"My body morphology was like an anorexic," Lietz said. "You never see yourself as tan as other people see you."
The problem with a mentality like Lietz's is that visual information gets processed piecemeal, and the focus is on a single aspect of appearance, such as skin tone, rather than the overall look.
"They can't see how a certain skin tone only makes sense in the context of overall complexion," said Dr. Jamie Feusner, assistant professor of psychiatry at the University of California at Los Angeles. "Like, if you have blond hair and blue eyes, a little tan looks extra tan."
But even when body perception is not distorted, the rise in incidence of melanoma is not surprising, experts say.
"Teenagers are very vain," Lietz said. "They're not willing to listen to others' advice when it comes to appearance."
But this was not the first time women switched to the dark side.
Before the 20th century, light skin was a privilege of the wealthy and aristocratic. Ancient Greeks, Victorian ladies, and Southern belles went to lengths to protect their skin because dark skin was plebeian.