Edema experienced in specific geographic locations

When I visit family in Montana, I experience significant swelling in my legs, ankles, feet and hands.  It takes a couple of days to develop and when I return home a couple of days to subside.  While I'm there, I take OTC diuretics and Benadryl because it is so very uncomfortable.  The diuretics don't help a great deal so I still have quite a bit of fluid under my skin but at least I can squeeze my feet into shoes.  I am well-traveled both domestic and international all at varying altitudes and this affliction has occurred only in this specific location in Montana and in the Phoenix area.  I live in Seattle.  My doctor is stymied so I'm hoping someone in the community has thoughts on the cause and/or how to better manage this issue since I'm unable to avoid either location.

[tschock]

Wow! It's going to be quiet the ordeal to figure out exactly what it is that's affecting you.

I'm not from the U.S so I'm not sure of what sorts of "weeds" and such that you have there.  I know that here in Canada some weeds only grow in certain provinces.
Check to see what weeds are different, as this MAY be the factor.

Are there different foods that you "only eat while visiting"? Perhaps you only eat apple pie while visiting cousin Mary, and only eat Uncle Frank's meatloaf?
Whenever I go to visit my mom I get sick. The reason? The town where she lives has a pulp mill...something we do not have.
When my grandparents were alive I used to get sick when visiting because they had a farm with many animals.

Not sure what to tell you, except avoid salt like the plague before going to these two places, and take allergy medication ( starting at least a week in advance if you can)...might help a small bit.

I'll start "surfing the web" and see if I can come up with anything else.
Your job is to make a list of differences between those two places and everywhere else you have been. Sorry.
Start with airborne pollutants...factories, weeds/pollen.

Another question here....when you travel, is it by plane or car?
Just to those two places.
If you travel by plane, is it the same carrier each time?  For instance, do you always travel by Delta to get to those two places, and by American Airlines to get to the rest of the world?
If so it could be a cleaning agent that one carrier uses and not the other...or something else they use.

If you travel by car to get to those two places then perhaps the swelling is due to sitting for long periods of time.

Hope this helps a bit, and does not add to your frustration.