I think the most useful question isn't whether women are more prone to contagion. It's whether more women would be saved by a doctor's skepticism of their symptoms, or whether more women would be denied proper treatment by it.
People talk about the ways that doctors dismiss women's symptoms, but I've found that a lot of women dismiss or downplay their own symptoms, which further hurts their chances of getting diagnosis, let alone treatment. There may be a sort of feedback loop between dismissive doctors and self-dismissive patients. My own story in that department is that I wrote off a certain set of symptoms for years because they weren't serious compared to my "real", established problems, but an astute doctor pushed me to address them, and in the process we found out that they were caused by a much bigger underlying issue... specifically, an underlying issue that was also the reason my established problems weren't getting better. In that instance, skepticism would not have helped!
That said, and this might be controversial or uncharitable of me, but I think there can be a tendency for some women to fixate on their problems, which often makes them worse. (Does that contradict my "dismiss and downplay" observation? Maybe. Or it could just be that people fall into one camp or the other.) Sometimes it's garden variety hypochondria, and other times I think it's another type of feedback loop where you have problems that no one can identify and/or help you with, so you're suffering but not many people believe you, and your symptoms are unmanaged or only barely managed through a fragile collection of DIY measures. This puts you in a precarious position (understandably), which is obviously nerve-wracking, which in turn means you're either (1) hypervigilant to new developments in your condition, and so any change is a cause for alarm because you don't know what the implications will be, or (2) always worried that you'll deteriorate at a moment's notice, and the ensuing anxiety can cause your symptoms to worsen, so that anxiety becomes a self-fulfilling prophecy. (Ask me how I know, lol.)
There's also a saying I've heard along the lines of "you can't get better if you have to constantly prove you're sick," which I think applies to a lot of people who are struggling to get taken seriously by doctors: not only are you not getting proper treatment, but you're also in a position of having to prove the legitimacy of your issues, which means that any spontaneous and/or self-medicated improvement in symptoms might be a sign that the people who think it's all in your head are correct. (The implications here could be internal, in the sense that part of you worries they're right, or external, in the sense that you know they're wrong and can't let them think they're right.) After you figure your shit out and stop having to "perform" for people all the time, it's easier to allow yourself the space to get better—because now your problem didn't go away, exactly, it's just responding to treatment, or it's in remission, or so on. The validation of a proper diagnosis creates a kind of permanent road marker that lets you move on from it, but still point back to the road marker when you need to.
Another thing that's a slight tangent, but I think still relevant to gender disparities at play: sex hormones play a HUGE role in certain conditions. Most people won't realize the extent to which this is true unless they've undergone drastic differences in the types of sex hormones in their body over the years... but I have, so let me share my experience in that department :)
- High/unmodified estrogen: The worst. Things were always bad, but obviously much worse at certain times of the month.
- Using progesterone to lower estrogen levels: Significantly better, although still a fairly crummy baseline. Those times of the month were far less bad.
- Using testosterone to suppress/lower estrogen levels: SO much better, holy shit. It's hard to even describe. Not just the obvious things related to strength and muscle mass; there's an overall sense that certain things have generally calmed down. (Also, now no times of the month, which helps too :P)
My wife and I used to interact a lot with newly married couples at our church and if our experience is anything to go off of, you are correct and it's the one thing that drives new husbands crazy.
I don't think there's anything wrong with saying it. It's a generalization and doesn't apply to everyone, but it seems obvious to me that there are social pathologies that are sex-specific. As a man, I can rattle of dozens of pathological psychological us men are especially prone to. I think there's actually widespread recognition of this for men. I don't see why we shouldn't be able to say the same thing about women.
That's not to dismiss women. After all, the desire, especially of young men, to one up another is absolutely real (and can sometimes become destructive)! Or, the desire to simply grin and go on despite having some kind of emotional need is again a very real desire in many men. However, society realizes this and has actively tried to at least make men aware of these various states of mind that affect us. Whereas -- again if my experience as a mentor to new couples is right -- if someone ever tells a women that she is falling into a stereotypically female doom spiral, woe be to that man, or woman (in general, of course, there's always exceptions!)!
And that's a very strange reason to be skeptical of womens' description of their symptoms in a medical setting. Is there evidence that women are more prone to 'social contagion'? You yourself said that "women are more prone to auto immune diseases" and that they are known to be triggered by viruses...To me, skepticism (and in my view, cynicism) of patients is one of the major contributors to distrust of evidence based medical advice.
Taking your last anecdote as an example, just because the patient's self diagnosis is likely incorrect, that does not mean that the symptoms they're experiencing are all "made up" and should be met with skepticism. There may be other reasons they're experiencing symptoms. A doctor shouldn't just say "Because you thought it was long COVID even though you weren't diagnosed with COVID, I'm convinced you're making the whole thing up". That's just lazy and unsound.
On the other hand, Lyme blood tests are pretty cheap. And what the "Lyme literate providers" (aka grifters) don't mention is that some of the cheaper blood tests are prone to false positives in the presence of inflammation. Which most people with autoimmune diseases have :)
It took me years to get to the bottom of my own shit, and if I'd taken the Lyme test (that one of my doctors inexplicably ordered years ago) at face value, I'd probably be taking a sketchy cocktail of supplements and antibiotics right now instead of what I really need, which is Remicade.