I would suggest that you do three things.
1. bring your problem to the attention of the person responsible for health and safety in your workplace who has a duty to investigate.
2. see your doctor to see if the cause of your problem can be identified.
3. check your home to see if that is actually where the problem has arisen especially if you have pets.
I was responsible for H & S in my workplace for nearly 20 years and on average twice a year someone would tell me that the offices were infested with something because they were itching or coming out in a rash. Never once in that time were we able to find any cause in the offices and, in the majority of cases most of the affected people reported back that they had discovered some other cause and that was mostly animal fleas from home.
Some other points. If you make your work colleagues aware of your problem then most of them will find a spot, pimple or skin blemish somewhere on their body and will claim to have the same problem as you. If your employer does what I used to do and make everyone aware that all the offices will be sprayed on a certain night (and then does precisely nothing) and tells them the following morning that it was done, then everyone except the original complainant will have no more problems.
I'm not suggesting that your problem doesn't originate in your workplace and refer you back to my original 3 points so that you check more than one possible cause.
Best of luck because it is always a real annoyance and often very difficult to pinpoint the actual cause.