7 On Your Side first reported this problem in January after many Force users began noticing blisters right where they wore the tracker. At first Fitbit said there were a small number of victims, but reports kept coming in, and still are. Fitbit pulled the product off the shelves and now untold numbers are left with a rash and a mystery -- what in the world were they exposed to?
San Francisco resident Matthew Kovinsky liked how his Fitbit Force counted every step he took, every mile he ran. He didn't like what it did to his arm
"Once I got a really bad rash I really hated it," he said.
Kovinsky had worn the device for weeks before itchy red bumps suddenly broke out under the tracker. He put it on his other arm and it broke out too.
"I'm worried I don't know exactly what it is," he said.
Kovinsky went to Fitbit's online forum; there he found thousands of comments about Force users with the same rash.
"So it's not just me and it's time to figure out what happened and why it happened," he said.
Fitbit said very little at first, saying there was, "a very limited number of Fitbit Force users who have been experiencing skin irritation, possibly as a result of an allergy to nickel."
However, many on the forum said they are not allergic to nickel. They began sharing theories and ideas for treatment.
Massachusetts resident Kim Reichelt got an oozing rash weeks after she started using it. She began gathering her own data about victims.
"I read every post and if somebody said 'I had the rash,' I put their name on a list," she said.
She put the list online with 198 victims. It quickly grew to nearly 800. Many said they wore the band for months before a rash broke out.
The company said it hired an independent lab but there was no definite cause. Many suspected the charging port where the blisters started.
"Maybe it's just a rash, maybe it's like getting poison ivy and it will be fine, but maybe there is something toxic in my blood stream," Reichelt said.
7 On Your Side consulted with UCSF and Kaiser dermatologist Golara Honari. She said nickel allergies cause itching and redness, but large blisters like these are uncommon
"We've seen very severe nickel allergic reactions, it's not typical but it's been seen," Honari said.
Fitbit said 1.7 percent of users reported a rash, but would not say how many that is. Last month, Fitbit pulled the product off the shelves.
In a statement, CEO James Park said, "From the beginning, we have taken this matter very seriously. We hired independent labs and medical experts to conduct a thorough investigation. ?Independent test results have not found any issues with the battery or electrical systems...test results show that users are likely experiencing allergic contact dermatitis. ...some users may be reacting to the nickel present in the surgical stainless steel used in the device. Others are likely experiencing a reaction to materials used in the strap or the adhesives.''
Kovinsky says Fitbit is supposed to make people healthier.
"It's done just the opposite for me," he said.
Fitbit declined 7 On Your Side's repeated requests to release information on what materials and chemicals are present in the tracker. The company is working with the Consumer Product Safety Commission on a comprehensive recall plan. It did not say whether that means everyone will be told to stop wearing the device. We expect that information in a matter of days.