Son has bumps on arms and hands for about a week. itchy but not red. what could this be and how can i treat it?

Itchy bumps: Without knowing a little more about the appearance of the bumps and without seeing the rash/bumps themselves it is difficult to say. The best approach would be to have his pediatrician take a look, then if medication is required it can be prescribed. Some of the possibilities that come to mind are: scabies, arthropod bites, atopic/allergic reaction, hyperkeratosis (not generally itchy tho)…...