Signs of a staph infection can include but are not limited to having a small red bump that resembles a blister or a pimple, a boil or an open sore or skin ulcer. When a sore becomes infected it is often red, warm and tender surrounding the area. Sometimes discharge of pus, a yellowish-white fluid that may have a bad odor and fever may be signs also. Staph infection can quickly progress and get worse. If you think you have a staph infection contact your doctor immediately. Certain kinds of staph infections can be deadly if they are not treated in a timely manner.