If a person keeps getting various infections in a similar part of their body, for instance a cavity, followed by an irritated eye, followed by an ear infection, followed by an infected piercing all on one side of the head, could it be one infection spreading? Do infections spread in such a way? Could it spread to muscles or bone or other blood or down the body? Does it tend to stay on one side or the other like migraines or shingles?
Comments
No, those would all be tiny superficial infections (if they are infections at all) that have come externally.
An infection that spreads inside the body either invasively or in the blood is a medical emergency likely to land you in the ICU or kill you if it isn’t managed fast enough.
Infections can spread internally, but it’s a pretty big deal when it happens. https://en.wikipedia.org/wiki/Bloodstream_infection
More likely in this scenario is that the infections are either entirely unrelated, or are spreading externally- maybe you touched your eye and piercing site while your hands were dirty.