He may have allergies which, if treated, will help. You definitely don't want to make more of it than you have to. You can try a small reward system of some kind. Also something to keep his hands busy like action figures or a little hand-held game. I'd stay positive and gentle about this so you don't inadvertently make it worse. It is disgusting but not abnormal and he should grow out of it - the sooner, the better, for your sake!
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He may have allergies which, if treated, will help. You definitely don't want to make more of it than you have to. You can try a small reward system of some kind. Also something to keep his hands busy like action figures or a little hand-held game. I'd stay positive and gentle about this so you don't inadvertently make it worse. It is disgusting but not abnormal and he should grow out of it - the sooner, the better, for your sake!