Can stress cause geographic tongue? I developed this after a very long stressful period and it seems to be better with stress reduction.

The cause is unknown. The cause is unknown as is the role of stress in causing it. I am glad to hear that your stress reduction is seeming to help, because we typically are unable to do anything about it.
While the cause of. Geographic tongue is unknown, there may be a genetic link or it may be an autoimmune response. Stress often affects our bodies both in proven and unproven ways. It can often be a factor without a direct cause effect relationship and therefore may well play a role in your particular case.