Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Get emergency help for rapidly worsening illness, confusion, difficulty waking, trouble breathing, extensive skin peeling, or rapidly spreading redness with severe pain.
These are not usual features of uncomplicated impetigo.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Arrange a routine or prompt medical assessment if you think you or your child may have impetigo.
Early advice is particularly useful when the affected person is a baby, has a weakened immune system, has diabetes, or has widespread eczema.
Seek same-day medical advice if:
Redness, swelling, warmth, or pain is spreading
There is fever or the person feels increasingly unwell
Sores are close to the eyes
Large blisters or deep ulcers develop
Treatment is not working as expected
The condition repeatedly returns
Dark urine, reduced urination, or facial or ankle swelling develops
Every sign above is quoted from the sofidex article on Impetigo. If you are not sure, err upward — it is always reasonable to be checked.