My 4 yr old son just got bit by some kind of bug. I didn't see it and neither did he. I wouldn't be worried, but it's swelling a bit and there are these small red lines radiating up his arm (it's just below the krook on the inside and they resemble small stretch marks) I've never seen a reaction like this and want to know if anyone else has. I would just call the dr, but my husband has the phone with him. I did put cortizone 10   on it. Does anyone know if this is serious?

ask your neighbors. depending on where you live look up bug bite reactions(webmd.com might have something)and that should help.back to the neighbors. in every neighborhood theres someone that's obsessed with outdoors.ask that person,and describe he bite,or bring your son.

How funny, I live in the Upper Peninsula of Michigan and am annoyed by the mosquitoes already....so maybe it was one of them.  This was an answer to a question I found on another Yahoo Answers:  
http://answers.yahoo.com/question/index?...




So as someone else said, it may be blood poisoning...

But just get it checked out

sound like he may have been bitten by a brown recluse spider.  If so, they are very poisonous and could cause sever swelling and a lot of pain.  I would take him to the hospital and get it checked out.

If he has red lines radiating from the bite out and up his arm GET HIM TO THE DOCTOR! The red lines can indicate blood poisoning.   I say  "can " but may not.  Better to be safe than sorry.

U DONT HAVE A HOME PHONE?? IF U DO PHONE