CORAL GABLES, Fla. -

South Florida doctors are seeing younger cancer patients.

In 2002, Jonathan Loynez developed skin cancer at the age of 7.

"It looked like a mole on my foot and we thought it was a wart but wart medication didn't work," he said.

A biopsy revealed that Loynez had melanoma.

While skin cancer is rare in children, parents need to watch out for moles that change and follow the A-B-C-D's of recognizing skin cancer, say doctors.

"Any mole that has an asymmetric shape, irregular border, irregular color or change in diameter needs to be evaluated," said Dr. Ana Margarita Duarte with Miami Children's Hospital.

While skin cancer in children is typically genetic in nature, Duarte said sun exposure in childhood dramatically increases risk.

"Eight percent of our sun exposure occurs in childhood and one blistering sunburn doubles your risk of all kinds of skin cancer," said Duarte.

Now Loynez, 17, makes visits to the dermatologist part of his routine and knows he has to be careful about protecting his skin from the sun.

"I see my friends getting dark and darker as they play sports and I say 'Hey, you've got to be careful with that,'" he said.