Thank you for all the information,
There seems to be a foot infection.
Infection can enter through minute cracks & can then enlarge.
As he is prediabetic, this needs to be treated urgently.
In diabetic or prediabetic conditions, infection can spread rapidly.
His blood sugar needs to be checked again.
I would suggest to seek urgent appointment with his doctor or see doctor in an urgent care.
You can apply neosporin cream.
I hope this information helps.
If there’s anything else I can do, please let me know.
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