Thank you for your query,
This condition may be examined physically by a Pediatrician
as with narration it is very difficult to diagnose.
Please send clinical photograph of the picture to comment and give you proper advise.
This is not looking like pus filled lesions, as they may cause pain, irritation and some times fever
It is looking like keratosis pilaris
but should be seen by doctor to confirm and to advise specific medication.
Hope I have answered your query.