How should I treat the small bumps that appear on my 12-month-old's feet?
It sounds as if your son develops an irritant contact dermatitis, a skin irritation due to the friction that occurs when he crawls. You seem to be doing a great job, though I would recommend a petrolatum-based barrier ointment (like Aquaphor), which may speed healing. Putting on some "pre-walker" shoes may also lend some protection for his small feet. Soon, of course, he'll be walking and all of this will be only a memory!