But what you actually said is this:

if the patient had been seen by a dermatologist I would be surprised if this would have been missed.

I was diagnosed in my mid thirties with a genetic disorder. It is a more recently recognized milder manifestation of a well known condition. Prior to that, I was basically treated like a hypochondriac and routinely accused of being lazy.

I have read a bit about the difficulty in getting a proper diagnosis. It is routine for people to get treated like they are nuts because the doctors do not immediately have the answer. This winds up being incredibly threatening. It puts you in a position of fearing for both your freedom and your life if you keep talking about your symptoms and keep trying to find an answer, while knowing that not getting an answer may well kill you.

When I had been on antibiotics for several weeks straight with no diagnosis, I expressed my concern that I could die if they couldn't find the answer. The doctor asked if I would like a psych referral. My legitimate concern that I could die in the face of being deathly ill and doctors failing to readily diagnose it was treated like I was merely being neurotic and needed therapy.

Doctors frequently do a terrible job of identifying anything that is at all obscure and they treat patients in a way that makes it both very challenging and genuinely threatening to even try to get a proper diagnosis. I did all in my power to not wind up hospitalized because I was relying heavily on home remedies, like hot baths, to keep my symptoms down to a dull roar. I was convinced that ending up hospitalized would deny me the ability to do that and would be the death of me because doctors can be such assholes at times.

After finally getting a diagnosis, I began growing stronger and healthier. I had always been sickly and did a lot of self care. I now had an explanation as to why I was always sick and it was very empowering.

People with my condition typically get regular checkups with a specialist four times a year. As I grew stronger, my doctor began scheduling me fewer checkups and expressed zero curiosity as to how on earth this was happening when it is supposed to be impossible. When I moved because I was getting divorced and could not afford to remain in California, I did not bother to try to find a new specialist. I can manage my condition better than a doctor can and I didn't want the hassle when doctors don't really want to see me anyway because, I guess, I'm too competent to be a desirable patient.

One outgrowth of that: people on the internet conclude I am some nutcase rabidly rejecting conventional treatment. Doctors did not really want to see me. I no longer need a physician's care. But good luck explaining that to legions of internet strangers who are quick to judge and have no desire to be confused with the facts.

If you have an obscure condition, it is not unusual to know more about it than most general practitioners will. This fact is not at all respected by the general public. Claiming you know more gets pissed all over in internet discussion.

The system does an incredibly poor job of serving most people with obscure conditions. Given the wealth of information and tools available today, I find it appalling that this is so.