Depends on the bug
As dr evans described, the "where" is key to understanding an infection.
Also, different bacteria
do different things to the body. Usually, though, there is some kind of "-itis." dermatitis
is "itis" of the derma or skin. "-itis" involves irritated or enlarged blood vessels, so these lead to redness, warmth, swelling, and pain or itch. Viruses can do the same, though, so not always easy to tell!