There are 5 allergens in pistachio nuts. Pis v 1, 2, 3, 4 and 5.
Pis v 1 is a 2S albumin, Pis v 2 and 5 are 11S proteins, Pis v 3 is a vicilin protein and Pis v 4 is a manganese superoxide dismutase which is a plant enzyme.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Pistachio.php
The allergy resources page for pistachio covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with pistachio.
There is also regularly updated links to useful websites specifically for pistachio allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.