Hi welcome to Health care magic forum. According to your description they appear to be utricaria, due to some thing which is allergic to you. There must be itching as you are not feeling it, it might be very little or your perception is less.
According to the severity of the rash
, anti histamines
and steroides are used to minimise the diffeculty. If there is no diffeculty or pain you can ignore it .
If you get it again, you should consult a physician for diagnosis and treatment. You should find out the allergin causing the rash,and avoid it .
Don't worry everything will be fine.