What Causes Vomiting, Itchy Chin And Heaviness In Limbs Of Child?

My 7yr old son for 2 days now has a body temp of 95.5/95.9 and now tonight he s dropped again to 96.3/96.7. He has started vomiting yesterday around 7:30pm. This continued until about 9:30am and he has not vomited at all today however is still complaint of butterflies in his stomach. He itched his chin so bad he left a 1/2 inch round mark(looks like he skinned it on tar) he said it just itched. That started Saturday morning when he woke up. His normal temp is 99.1 and he is my high fever running baby can get up to 104.5 when he is sick.. My concern is he shows no other fly like symptoms other then the 15hour spat of vomiting. No real behavior change except he spaced out at around 7pm tonight just saying he was thinking. Has complained about feeling heavy in his arms and legs.. And since day 1 has had bowel movement issues.. Last bowel movement was Friday about 6pm. What does all of this mean? Seek medical attention or did he pick up a different kind of bug and just needs rest?