Are there tests for psoriatic arthritis?

[Fred]

I've never had an ultrasound test for psoriatic arthritis so I don't know.

My dermatologist and rheumatologist both said they could tell by just looking at my finger nails and prodding me about a bit. Nails apparently are a good indicator of psoriatic arthritis.

Bloods can show inflammation changes but I'm not sure it can tell the difference between psoriasis inflammation and psoriatic arthritis inflammation.

I've never had a specific test for psoriatic arthritis but my dermatologist and rheumatologist have both confirmed I have it. Oh and I know I have it without anyone confirming it for me.