Kindly visit MDS pedodontist for treatment. The reason of pain and infection is decay. Pain will not go away till the decay is removed. RCT or extraction will depend on x ray. If not treated, permanent teeth will also get infected.
Next Steps
Kindly visit MDS pedodontist.
Health Tips
Do not try any home remedies. They are more harmful than useful.
Apply ice from outside if any swelling is there.