The baldness began in February with 90 airmen deployed to Shindand Air Base, Afghanistan.
It has since spread to Air Force bases on two more continents — to Italy, North Dakota, Arizona, Florida and places in between.
More than 400 airmen have shaved their heads in support of 5-year-old Brayden, whose father, 2nd Lt. David Mitchell, died in a pilot training mission just before the boy was born in 2008.
A January hospital visit for what doctors thought was appendicitis ended with a cancer diagnosis when a surgeon discovered an egg-sized mass on Brayden's kidney, his mom, Kristi, wrote on a Facebook group called Brayden's Backers. In the months since, Brayden has endured surgeries, chemotherapy and radiation.
When Brayden was discouraged over the loss of his hair, Kristi posted a message on the social media site asking if anyone would shave their heads in support of him.
"I was more than willing to do that," said Capt. Corey Preston, who went to pilot training with Mitchell. Preston decided to make an event of it at Shindand, where he was stationed at the time, and take a bunch of photographs so Brayden could look at them.
In late February, Brayden watched over video chat from Ohio as more than 90 airmen went bald in his honor.
Capt. Michael DeVita was inspired when he read what Preston and the others had done. Mitchell and DeVita flew T-6s and T-38s together during pilot training, where they became best of friends, he said.
"I talked to Kristi and thought we could get something going here," DeVita told Air Force Times.
DeVita and 17 other B-52 pilots from the 23rd Bomb Squadron at Minot Air Force Base, N.D., followed suit, taking a picture of their shiny bald heads to send to Brayden.
At Aviano Air Base, Italy, a dozen F-16 pilots from the 510th Fighter Squadron did the same.
Luke Air Force Base, Ariz., "painted Brayden's name on one of the airplanes there, the same one Dave had his name on," DeVita said. "I've seen pictures of [pilots with shaved heads] in front of the F-35 at Eglin [Air Force Base in Florida], at Aviano, all over the place. It's incredible how fast it's moved around the world."
At last count, at least 10 bases have hosted "Go Bald for Brayden" events, Preston said. A handful of women have also shaved their heads — one a Defense Department civilian employee and one a female airmen, even though it's against Air Force regulations.
Many of the airmen never even met Mitchell, he said. "Everyone's been asking for his address and mailing [Brayden]photos," DeVita said.
"He thinks it's so cool to see all of the support he has been getting from the military," Kristi said in an email to Air Force Times. "I'm not sure he totally understands how big of a deal this really is, but he will one day."
For Kristi and her fiance, Nick, "it makes a difficult time a little bit easier to know we have so many people behind us," she wrote. "To do something they may think seems like no big deal makes our little boy light up and there is nothing better than seeing him smile."
DeVita remembers how happy Mitchell was when he learned he was expecting a son, his first child. Mitchell had gone from working on jets as an enlisted Air National Guardsman to flying them after earning his commission. He died in an F-16 crash outside Luke in March 2008, just four months after he arrived there for fighter pilot training.
"He worked really hard to become a pilot," DeVita said. "He excelled the whole time. He was always there to help anybody in the flight, if they were ever struggling. Instead of going home early, he would stay to help the other guys."
Which is partly why DeVita wanted to do what he could to make sure Brayden feels supported during his cancer battle.
Wouldn't it be something, he said, if Brayden grew up to be an F-16 pilot like his dad, and the kindness Mitchell always showed went full circle?