I agree with this 100%, and would also add that (while a workout will typically do it on its own) you should fix your posture immediately.

One of the major things I notice when my wrists start getting irritated is that if I sit up straighter it helps. There are nerves running from thumbs to mid-back, and posture affects them immensely. Simply sitting correctly may (or may not, depending on how bad you habitually sit) be easier than exercise and provide more immediate remedy.

Still, exercise. Definitely.