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
Seek urgent or emergency care if a rapidly spreading rash occurs with fever, chills, confusion, faintness, severe weakness, or red streaks extending away from the area.
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
Seek prompt same-day care for rapidly increasing pain, warmth, swelling, or spreading redness or discolouration.
These changes may indicate a bacterial infection.
Severe pain that seems greater than the visible skin changes also needs urgent assessment.
3
Does any of this apply?
Book an appointment
Arrange routine medical advice if:
The rash does not improve with gentle drying and skin protection
It keeps returning or the cause is uncertain
There is cracking, bleeding, pus, crusting, or a strong smell
Over-the-counter treatment has not helped
The rash involves a baby, a medical device site, or a large area
You have diabetes, poor circulation, or a weakened immune system
Every sign above is quoted from the sofidex article on Intertrigo. If you are not sure, err upward — it is always reasonable to be checked.