I have a 3y/0 with c/o back pain x 1 yr. Mri negative and UA with wnl. Pain is intermittent and he only complains when lyin down or in his car seat. i have noticed his lips get pale when lying or sitting. This concerns me about cardiovascular system. He doesnt demonstrate any dyspnea, labored breathing, or anything that slows him down. He is very active and is physically completing 5yr old task that were done by pediatrician. I find this very confusing because there is no pattern.....HELP!!
I can understand your concern since back pain in children that young is very rare. I would suggest asking your son's pediatrician for a referral to one or more specialists to further investigate possible causes. It seems like the pale lips should be a clue. If it were me, I think I'd follow your mother's instinct and check into possible cardiovascular problems. Maybe the pediatrician can recommend a cardiologist – preferably a pediatric cardiologist.
Here are a couple of articles on back pain in children that list some of the possible causes:
Back Pain in Children by the American Academy of Orthopaedic Surgeons
Back Pain in Children by the National Pain Foundation
Don't let doctors brush you off or ignore your concerns. Keep trying different specialists until you find one who can tell you what is causing your son's pain. I wish you the best in your search for an answer.