Finding a specialist for Essential Thrombocythemia

Hi there. My husband has "pure" ET (which I'm assuming means it is from a genetic flaw, but I really don't know) and has been on hydroxy for years. But two years ago he got a DVT in his leg and is now on a heavy-duty blood thinner - Lovenox, a twice-daily injection. (There were serious complications that landed him on Lovenox from one of the more common oral blood thinners, including a clot in his heart.) Since the onset of the DVT and the introduction of a blood thinner he has developed multiple foot ulcers. They are incredibly painful and often get infected. He has been seeing a wound care specialist once a week for over a year now to treat them, but can't seem to get rid of them. When one finally starts to heal another pops up somewhere else. These ulcers have reduced a once healthy active man to someone who has difficulty walking to the mailbox. We are losing hope and the doctors here in southern New Hampshire have no solutions, other than to switch him from Hydroxy to Interferon, which so far has not changed a thing. I think its time to find a specialist for ET, but I don't know where to start. Any guidance would be much appreciated.