We reported a while back that some Fitbit users were reporting that their devices were causing them discomfort – from mild chafing to full on allergic reactions.
It seems that the company has finally heard the growing complaints, as the Wall Street Journal has confirmed that Fitbit is now conducting an ‘extensive investigation’ into this.
The Fitbit has been a critical success so far
In a statement, Fitbit Chief Executive James Park said the company has been conducting “an extensive investigation,” and believes the skin problems are “allergic contact dermatitis, which can resemble a sunburn or a rash.”
In a blog post last month, Park said Fitbit believed the rashes were most likely allergic reactions to nickel, a component of the steel in the Force. “Our investigation is looking beyond nickel to other potential causes as well,” a Fitbit spokeswoman said.
In January, Mr. Park wrote that tests by an independent lab had ruled out a mechanical or electrical defect. Fitbit has begun offering refunds or exchanges to unhappy Force customers.
Fitbit released the Force in October, and complaints started before the end of 2013. The company says the device can “track steps taken, distance traveled, calories burned, stairs climbed and active minutes throughout the day.” At night, it tracks users’ sleep patterns. Data can be seen on the wristband’s display or on a smartphone or computer.
We’ll keep an ear to the ground regarding any further developments, but in the meantime, if you’re suffering from any issues, you can contact the company via their website.
Tech Runner 
Here’s my analysis on why this isn’t a nickel allergy.
Among users who have reported their rash on the Fitbit help discussion forum (520 to date), here is little difference (and very likely no statistical difference) in the reaction onset time for people who have had a past nickel allergy and those who have not. Admittedly, the sample size is small for people who have had a past allergy (but that alone should be a clue), but to date we have 153 data points (people who have reported both reaction time and past allergy status):
People with a nickel allergy: 32 days to onset (n=10)
People w/o a nickel allergy: 36 days to onset (n=143)
What do we know?
1) no difference in rash reaction time for people with and without past nickel allergies
2) very few people who have reported allergy status who have had a past nickel allergy (10 of 153 who have indicated)
3) several posters have noted that since developing the rash they been tested for nickel allergies and had the test come back negative
4) several people have posted that they have severe nickel allergies and have had no reaction to their Force
Therefore: it seems highly unlikely that these reactions are to nickel.
The big question: If it’s not nickel, what is it??