3 yr old,ultrasound revels lymph nodes in upper cervical region bilaterally relatively larger on left side with largest measuring 13mm by 6mm intact h?

Rather common: These nodes are often found exposed because they are not buried in tissue folds or fat. They enlarge in response to local or general infection, vaccines and tend to enlarge & shrink back to resting size over 3 wks. Any further comment would require more information to put this finding in context. At this point the node is neither unusual or of an unusual size.

Watch and wait: You may feel the nodes every couple of weeks, if any of the the lymph glands doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or the child develop fever, or loses weight, you should see a doctor. Wish your child good health!