While both cause bumps, pimples, and redness, one big difference between acne and rosacea is the redness. With rosacea, that redness will be more widespread and in the middle of your face. With acne, it will be mainly around the pimple(s). Also the treatment is totally different and rosacea happens in older people. Acne can happen on your jawline, cheeks, chest, back. Rosacea only happens on the face.