Sorry to hear that it has taken so long for you to get a diagnosis of PN and AN - it's unthinkable really!
However from my understanding (and it’s awhile since I’ve done research on this) these (PN & AN) are generally symptoms of other conditions. One of the articles I found very explanatory at the time I was researching this topic can be found at this link
http://www.aafp.org/afp/980215ap/poncelet.html This paper is getting a bit old now – 1998 - but it still has a lot of fundamental information. It is possible that some medical conditions have been added to this algorithmic list since then but looking at other papers may reveal newer listings.