Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency care for breathing difficulty, throat or tongue swelling, collapse, a seizure, inability to wake the person, severe confusion, or signs of a rapidly progressing allergic reaction.
And for anyone, someone who:
Promptly contact a clinician for repeated vomiting, ongoing diarrhea, worsening rash, facial swelling without breathing difficulty, reduced urination, or symptoms that are not improving as expected.
After a minor exposure, routine follow-up may not be needed if the person remains well and symptoms resolve.
Arrange nonurgent medical follow-up if a treated wound is not improving, a localized rash continues after bacitracin is stopped, or there are questions about safer wound-care options.
Plain petroleum jelly and a clean dressing may be suitable for some minor wounds, but wound care should be matched to the type and severity of the injury.
And for anyone, someone who:
The article also says
Follow the observation instructions provided by Poison Control or the treating clinician.
After a suspected allergy, ask whether bacitracin should be added to the medical record as an allergy.
Check labels carefully because bacitracin may appear in combination antibiotic products.
A clinician or pharmacist can help identify alternatives when a topical antibiotic is truly needed.
Every sign above is quoted from the sofidex article on Bacitracin zinc overdose. If you are not sure, err upward — it is always reasonable to be checked.