Finger injuries are very common in children, particularly the finger tips. Many times, as with your nephew, if the injury doesn’t appear to be severe, it isn’t treated but it can develop into an issue that needs to be addressed later on.
At this point, your nephew, if he has not already done so, should see a doctor to have his finger evaluated. Depending on what the injury may be, your nephew’s finger might be corrected through splinting or surgery.