Doctor confirmed my child has deep venous thrombosis and will need to follow up. will this be a longterm problem?

See vascular spclist: Leg swelling can sometimes be a recurrent or persistent problem. Wearing support stockings for a year or two may be helpful. Your child should see a vascular specialist. Also a hematology evaluation may be necessary to see if your child has a hereditary tendency to form blood clot.

Yes: It is extremely unusual for children to develop dvt. Your child should be evaluated for hypercoagulable states (tendency to clot). A hematologist/oncologist would be a good choice for this. Dvts can cause longterm problems depending on how extensive the clot is. Compression stockings are a good idea to control swelling and prevent skin problems. Your child should be on blood thinners now.

Likely: As drs. Harris and ananthram said, blood thinners are a must as well as a hematology evaluation. Graduated compression stockings are essential to help reduce the possibility of developing post thrombotic syndrome down the road.