Please know that I am not a doctor or dermatologist.
I guess the first thing I would suggest is to get your child checked out by a pediatrician. If he has the same kind of rash I would wonder if this is contagious.
Do either of you have other symptoms? There are certain viruses which can be spread and affect the mouth area like Hand, Foot and Mouth disease.
The Dr. Sears site has a very good explanation of the symptoms of childhood rashes which you may want to take a look at.
Do either of you have eczema or hives?
You won't know what this is until you are both seen by a doctor. I would make an appointment soon.
Thank you for your question.
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