When I have a flare up the affected joints itch but it is like they are itching on the inside, under the skin.

Thanks

Shingles is a long lasting condition with itching, pain, burning, and a nest of other pleasant experiences extremely difficult to stop. So sorry for your suffering, hang in there. Have you tried hydrocortisone cream or lidocaine cream? There's a 5% lidocaine cream called Recticare. Since its safe enough for hemorrhoids, it might be helpful and safe enough for what you're dealing with.

Nerve damage is my guess