Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services now if you or someone else has:
And for anyone, someone who:
Contact a poison information service promptly after swallowing an unknown, industrial, solvent-based, or large amount of ink.
Do this even if symptoms have not started.
Have the product container or label nearby if possible.
Seek urgent medical advice for persistent vomiting, worsening dizziness, coughing after inhalation, eye symptoms that remain after rinsing, or a painful chemical burn.
A tattoo should be assessed promptly if redness is spreading, pain or swelling is worsening, pus is present, red streaks are moving away from the area, or you develop a fever or feel unwell.
Routine medical follow-up is appropriate for a mild but persistent rash, a raised or itchy tattoo reaction, or symptoms that are improving slowly.
These situations are not usually emergencies unless they are accompanied by breathing difficulty, facial swelling, faintness, or rapid worsening.
Every sign above is quoted from the sofidex article on Ink poisoning. If you are not sure, err upward — it is always reasonable to be checked.