Son has small puncture/hole the size of pencil eraser in back of his throat. do we seek medical attention?

Yes: Although, you may be looking at the space between two lymphoid follicles in the back of the pharynx (throat), you need piece of mind that this is not an ulceration from a virus. See an ENT doctor for a correct diagnosis. Also has he had his tonsils removed? You may be looking at the result of the surgical healing.

Yes: Go to the emergency room tonight. There is the potential for a serious infection.