Well, what immediately comes to mind is hives:
Yes, stress can cause hives, also known as urticaria or a stress rash. When you're stressed, your body releases chemicals that can cause inflammation and make your skin more sensitive, which can trigger hives. Hives can appear anywhere on the body, but are often found on the face, neck, chest, or arms. They can vary in size and shape, and may be itchy or cause a burning or tingling sensation. Hives usually only last less than 24 hours and go away on their own, but they can come and go in waves and flare up for weeks. If hives last longer than a few days, you should see a doctor. You should also seek immediate medical attention if you have symptoms like fever or swelling of the mouth, tongue, or lips.
Had further thoughts on that. The argument about 'stress' is about something objectively testable and verifiable, and within the domain of science - they can measure cortisol levels in the blood (actually had that test done at one point - they were normal) and detect infections and even directly detect a suppressed immune system that can make infections more virulent.
It's still an incomplete theory, mind you, as it still leaves unanswered, the question of what's the physical mechanism by which your thoughts or mood raises those cortisol levels - but that's the big one, the relation between consciousness and the physical world, mind and matter, and maybe it's unfair to ask for an answer about that, possibly it's something that will never have a scientific explanation.
That's very different, however, from saying, after failing to find any such raised cortisol or infection, that your symptoms are somehow caused by your 'subconcious' and constructing some sub-literary theory of how those subconcious motivations relate to your symptoms, as if there's somebody else in your body with you making it do those things. Which is what the Freudians and those influenced by them seem to go in for.
Or just declaring it's all your fault for not reassessing and challenging your 'irrational negative beliefs', which seems to be the underlying assumption behind CBT.
The change in psychiatric fashion from the former to the latter seemed to follow, in lockstep, changes in the political climate - something that further makes me suspicious as to the fundamentally-political nature of 'psychiatry'.