I have an unexplained medical question. About 2 years ago, I was bitten by something (spider, I think) and my Left hand swelled up. The swelling has not gone down. Do you have any medical knowledge of what might be the cause? Are there any different tests that I should request? More information is listed below.

Like I said above, I was bit by something. I think it might have been a spider, but never saw the culprit. I woke up one morning and noticed my Left hand was badly swollen and had a red mark on the top of my hand. I let it go for about a week before going to the Doctor because there was no itching or pain. The Doctor gave me an ointment that had an antibiotic in it to reduce the swelling and kill any possible toxins. I used the ointment for about a week and there was no changes to the swelling. I waited a couple of months and went back to see the Doctor because the swelling hadn’t gone down. They ran a couple tests: 1)CT of my chest and neck area; 2)Upper limb duplex scan. Nothing unusual was found except for a cyst on my liver, which was found to be benign after doing an ultrasound. It’s been over 2 years and it’s still swollen. There has been a new finding since then: some numbness off and on in my arm. I’ve let all this go because I was getting frustrated that they couldn’t find any cause for why it was still swollen.