Suffer From Stuffed Nose, Brownish Mucus. Acne On The Cheeks. Viral Infection?

Hello - My son has a stuffy nose that isn't really running too much, but the mucous is yellow/brown and sometimes bloody from being dry. He also has some pimples under his nose that have turned pus filled (they are fairly small however). He also has a few on his cheek, one on his arm, and a few on his bottom (these are not pus filled, they are just pimples). Could this be an allergic reaction to something or a virus? Thanks