I smell of onion when I sweat and I don't know why

Hello,

for over more than a year I've been smelling of onions when I sweat. The first time I have been made aware of this was in the gym but hadn't even eaten any onion (nor garlic) for a while. I tried to find out if the smell is caused by a specific food by removing that food for a while and see what happens: nothing. The smell is still there no matter what I eat. It's also not a matter of hygiene, the smell also comes after I've just showered. There also does not seem to be any medical problem, I have checked with my doctor and mentioned the problem. Blood test looks very good. He recommended a visit to the dermatologist next, which I will do shortly. I also wanted to get a couple of ideas from here.

Here a couple of things I've noticed/learned since the smell began:

- it actually smells of onions
- I smell it sometimes, but it's elusive. I smell it only for a short while, like in a whiff (e.g. when I take off my jacket after coming home from a walk), then it's gone. I don't remember having smelled it more than once a day.
- other people seem to smell it the whole time I'm present (when sweating). it's very noticeable to them in the same room when I sweat. Especially in the gym, the whole room is aware
- by others it is described as smelling of onion or just smelling of sweat. I don't know if they're referring to the same smell though
- it seems to coming out of the arm pits and only when I sweat
- the smells comes very shortly after I start sweating! (bacteria is consuming the compounds in the sweat)
- when I sniff my arm pits (after having noticed onion), there's absoluteley nothing! Does it evaporate or what?
- I notice the smell more in the morning. I think I also tend to sweat more in the morning
- maybe stress-related sweat? Why wasn't it there before then?
- I'm very sure it's not food-related. I haven't changed diet much and the onion smell wasn't there before
- basic hygiene is in check My clothes are not the cause as well

At this point I really don't know what to try any more other than going to a dermatologist. Perhaps they will swab my armpits and analyse the bacteria. Maybe I have some bacteria overgrowth which is cause the smell or a microbiome that's off. But then again, why wasn't it there before? Any ideas?