blotchy red spots on face

I've been an Acne sufferer for some time now. Lately, i've noticed that my skin has been drier and very red. I don't know why, but sometimes when I sweat, or when i'm embarassed I get a bunch of big red blotchy spots on my face that usually go away within a couple of minutes. I've used many Acne solutions, and I'm currently on tetracycline, but I just wanted to know what these red blotches are and if they are related to acne.

~thx in advance Tweet