The description that you provide may indicate a kind of sensitivity called as presure urticaria and is caused by hyperactive immune protective mechanism.
However, this may also be a blister and there are several causes of blisters.
'Blisters are usually caused by injury to the skin from heat or from friction, which create a tear between the epidermis—the upper layer of the skin—and the layers beneath.
Short periods of intense rubbing can cause a blister, but any rubbing of the skin at all can cause a blister if it is continued for long enough.
Sometimes, the skin can blister when it comes into contact with a cosmetic, detergent, solvent or other chemical; this is known as contact dermatitis. This may also need to be ruled out.
It would be best to consult a doctor if it does not resolve on its own in a few days. Anti-allergics prescribed by a doctor may also be helpful.
Let us know if you need any other information.
i been having it for 4 years or so what ever hits my skin makes those rashes for example i work with boxes right so if 1 of them just hits me and rubs on my skin ,even if it is only for 1 sec of hitting/rubbing a rash will appear and sometimes it burns