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 trouble breathing, swelling of the face or throat, fainting, or another sign of a severe allergic reaction after using a medicine.
Contact the treating clinic promptly if a treatment reaction is more severe than expected, pain is difficult to manage, or the area develops spreading redness, warmth, pus, or fever.
These may be signs of infection or another problem that needs assessment.
Follow-up plans are individualized.
A clinician may recheck the treated area to confirm that it has healed and that the lesion has cleared.
People with numerous lesions, previous skin cancer, or a weakened immune system may need more frequent professional skin examinations.
Arrange a prompt, non-emergency appointment if a lesion:
The article also says
Between visits, it can help to examine the skin regularly in good light.
A mirror or help from another person may be useful for the scalp, ears, back, and other hard-to-see areas.
Note any spot that is new, changing, or different from the others.
Actinic keratosis itself is rarely an emergency.
Every sign above is quoted from the sofidex article on Actinic keratosis. If you are not sure, err upward — it is always reasonable to be checked.