"No pictures on this," Perdue said, before signing his name.
A few supporters eventually swooped to cover the scene with Perdue campaign sign.
The scene created a stir on Twitter:
The Perdue campaign later said that he was asked by the young woman to sign her diabetic pump "to help raise awareness for juvenile diabetes."
"This was a Georgia family who shared their personal story of their struggle with ObamaCare and the rising health care costs associated with their daughter's treatment which is not being covered by their insurance," said Perdue campaign spokeswoman Megan Whittemore.
Video of another angle of the exchange later surfaced:
Perdue supporters quickly shot back at those -- including The Washington Post -- who looked at the video and initially assumed that he was signing a torso.
Later, the Perdue campaign issued a statement on behalf of what it said was the Allen Family from Henry County, Ga. and provided a photograph of her signed pump.
"This video is extremely disrespectful to our family and our young daughter's privacy. We were shocked when we discovered this being taken out of context because our daughter requested to have her diabetic pump signed. This is something she has done with multiple other prominent figures and will continue to do in raising awareness for juvenile diabetes. We were surrounded by friends and family who understood our daughter's desire for privacy. We hope that the media and others will respect our wishes and make this go away for our daughter and our family."
Here's the photo:
American Bridge 21st Century also later said via Twitter that they "posted this video as it was recorded without commentary. We regret any confusion it caused."
Perdue faces Democratic candidate Michelle Nunn in a contest to succeed retiring Sen. Saxby Chambliss (R-Ga.). Three polls released Friday show that the race remains incredibly close. If neither candidate earns at least 51 percent support on Election Night, they will face each other in a Jan. 6 runoff.
Perdue was campaigning Thursday in Jonesboro, Ga., as part of a 10-day RV tour of the state that is expected to include at least 50 stops. He was scheduled to be joined Friday by Sen. Rand Paul (R-Ky.) and will make two stops Saturday with Sen. Ted Cruz (R-Tex.) in tow.
Why did this cause such a stir?
Because it would have violated the generally-held belief that it's probably best for candidates not to sign skin or cash money.
Former vice president Al Gore kept to the rule during his 2000 presidential campaign. At a stop at the University of Michigan, a young supporter put out an arm for the vice president to sign.
"I'm sorry. I don't sign skin," Gore said, according to TIME Magazine.
During the 2008 campaign, Barack Obama faced a similar predicament when a young child asked him to sign his hand.
"If I start that…plus Mom might not be happy when she comes home," Obama told the child before signing autographs in crayon on drawings they were working on during class.
In 2012 during his reelection, Obama also turned down an offer to sign a dollar bill, telling the young man who asked that it's against federal law to write on currency.
Karen Tumulty contributed to this report