Are there tests for psoriatic arthritis?

[Fred]

When it comes to PsA, you can't see most of the inflammation. So don't go by how much swelling there is.

My experience of psa was most visibly of swollen knuckles. I could hold left and right knuckles together and see the size difference. It also affected different knuckles at different times, including toes.

Just to throw in a bit more, I've had both of the above.  

From a huge sausage little toe that ended up almost as large as my big toe. To severe pain without being unable to unlock my fingers, but no swelling.

So as you can see Jim there is no 100% way of telling.  

I may be wrong but I thought ESR and CRP could also show high with a psoriasis flare in a person without psoriatic arthritis.

One thing for sure though Jim if you do get psoriatic arthritis, once you've had it a while you'll soon get to know what a nasty bugger it is.