I agree 1 (one) dose of Arnica is likely appropriate since it seems the injury would justify some complaining and your son is not doing so, but please do not give him a 200C Arnica 3 times a day.... also, you have stated there is no swelling or other symptoms to base any other remedy on... this is in fact an 'acute' condition and therefore a healthy 14 year old will likely heal well on his own and should be allowed to do so unless symptoms develope to indicate another remedy.... washing the wound with calendula tincture diluted in water or using one of the topicals Ricky indicated would be the most I would do in addition to 1 (one) dose of Arnica unless new symptoms develope, at which time you could post them so an accurate remedy can be suggested... just my opinion... Denise