For about a year now my son gets random sensation of being cut on the tip or side of his fingers sometimes it even gets very red when he feels this. it's been painful enough that it caused him to cry. last about a hour until the last time it hurt ti?

Could be nothing. However consult your Pediatrician as this could be something requiring a medical exam to accurately diagnose

Can it be assumed that these episodes are not caused by injury, or overuse while playing? Can you tell whether the joints are involved? If they're purely spontaneous episodes & if reddening of the fingers are present a type of arthritis may be the cause. I recommend consulting a rheumatologist for evaluation & advice. Any appropriate testing will be ordered.