Why do I have a pricking sensation at the surgery site?

After any injury (injury meaning either the abscess or the surgery) tissues get damaged. Nerves also get damaged. When nerves heal, they set up unusual communications. Therefore a touch sensation, which should stimulate a touch nerve, may actually communicate with a pain nerve and result in a pain sensation. Your concern is: Will this go away? The answer is Probably. Most such problems resolve in 6 months, but it can take longer. I realise that your pins and needles sensations have been there for some years, but I don’t think you have an option other than to wait.