What Causes Itchy Spreading Bumps All Over Body?

Red, itchy mosquito-like bumps randomly started to appear on my body one night. I first noticed them when I was scratching my back, but there seemed to be only a couple of bumps so I didn t pay it much attention. Maybe 15 minutes later I noticed there were. More. Not 15 minutes after that I undressed and looked in the mirror and noticed patches of red bumps that seemed to inflame the skin around them on my back, shoulders, arms legs, etc. I took a shower and scrubbed my body down to see if they would go away but I noticed even more bumps forming while I was in the shower. This has never happened before. I live in a Montreal where it has been quite cold for the past couple weeks. I haven t been in nature environment that could have caused exposure to bugs. Nothing about my daily routine changed, and I didn t start using any new laundry products or cosmetics, deodorants etc. at the time the bumps started to appear. The bumps aren t painful but are very itchy and seem to be spreading. Could it be allergies? Thanks