Over the past three years I've dieted for two weeks, annually, by virtually eliminating carbohydrates. It works very well for me as I mentioned last year. However, I've noticed an odd rash on my chest the last three times I've done this. At first I thought it was due to the heart rate monitor chest strap that I wear when running; perhaps my dog had licked it (he loved to lick salty stuff) and transferred some bacteria. But, that wasn't the cause.
A few weeks ago I tried treating one side of the rash with Cortizone to see if it responded without any luck so I made an appointment with my primary care physician. He was fascinated by the rash and said that he hadn't seen anything like that in his 24 years of practicing medicine. He gave me a few suggestions to eliminate variables that could cause it which I had already done. He joked that, perhaps, we had discovered a new disease that would get named after me and he'd get credit for the discovery. He took a photo of it and sent it to the dermatology department for a follow up appointment.
The dermatologist diagnosed it as transient acantholytic dermatosis and saw me today to biopsy it but it was virtually gone – as soon as I reintroduced carbs into my diet it began to clear up. I suggested that it was somehow related to ketosis when I came across this piece speculating that it was prurigo pigmentosa. The dermatologist said that he had just read a medical journal article about that condition and noted that the rash was different. After we discussed the cause some more he did some research to see how ketones are excreted by the body when eliminating carbs from one's diet. It turns out that keytones come out in sweat and are likely the irritant causing the rash in combination with my chest strap.
Just like my primary care doctor, the dermatologist said he was fascinated since my visit made him have to "think" and that he might write a medical journal article about it. Unless... of course... the doctors in this medical group are encouraged to tell their patients how "special" they are. Nah... couldn't be, could it?