Medicine The most common cause of renal scarring in a 3 year old child is: A Trauma B Trauma C Vesicoureteral reflux induced pyelonephritis. D Interstitial nephritis 💡 Explanation The most common cause of renal scarring in a 3 year old child is: ✓ Correct Answer: C. Vesicoureteral reflux induced pyelonephritis.