3 year old has swollen right hand?

My 3 year old woke up this morning with what appears to be a bug bite, however her whole right hand is swollen, red and warm.

I've searched for any punctures or anything else that may be suspicious, but have found nothing.

We don't have "poisonous" spiders up here, and the benedryl does not seem to have helped...

Is there anything else I can try or should I be concerned?

The spider doesn't have to be poisonous, all spiders have venom and if you are the least bit sensitive to it, you can have a bad reaction. If her arm is swollen, red and warm, she really needs to be taken to the emergency room.