I run a pet supplies business, i see all the time people coming to me with dogs which have problems (itchy skin etc) which have been put on steroids and various to control this.
A bit off topic, but I can relate to your comments about pets.
I took my cat off commercial cat food that contained fillers like corn, wheat and soy. After a few months on raw beef and raw chicken necks: her terrible flaky itchy skin cleared up, her fur shone and all the plaque on her teeth vanished. The vet said he was very happy with her wonderful turnaround. But he was not allowed to recommend the same to other pet owners, as his boss required him to sell medications and pet food formulas, as they were great revenue for the clinic.
Take out the word cat and inset the word human – take out the word vet and insert the word derm or doctor.
Pretty much the same thing really!
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Not many derms will advise you to change your dietary habits to help your skin because:
* They all need to sell medications for revenue too
* If all their patients help themselves with diet changes, said doctor/derm will have no patients left and be out of a job
* Most of them are nutritionally illiterate - the time allocated to nutritional studies is very limited or non-existent when doing a dermatologist or medical degree at university.
If you do a six year degree and only six hours in total is allocated to nutrition.......well you ain't going to learn much.

Plus I am pretty sure they are only taught from the outdated bog standard government food pyramid. It is pretty much slated towards large food corporations anyway - not worth the paper it is printed on.
The average dietician and nutritionist are also pretty bad in my opinion too, as they stick with this food pyramid and insist you must eat from ALL food groups – which is NOT any help to me because if I eat from the dairy food group, it will flare up my psoriasis, give me gut pains and give me arthritis pains.
In the end you often have to find your own path, rather than relying on the "expert" advice of others, who are really often nutritionally illiterate when it boils down to it. Sad fact is: I certainly know more than my medical doctor does when it comes to nutrition.
In fact, I have just read an article written by a derm on how to achieve perfect skin. From the ten points listed: botox was mentioned twice and diet not at all. Having just had my own skin professionally analysed during a beauty treatment and given a near perfect score, I certainly didn’t achieve this through having chemicals injected into or slathered onto my skin – it is all diet related.
Overall the most useful people I have found for dietary advice are natural medicine doctors and naturopaths. They seem more knowledgeable than most, especially if they are very experienced in a certain specialty areas like Raw Veganism or the Food as Medicine concept. Plus of course most of my gems / lightbulb moments have come from my own research (lots of reading) into the subject and mainly from my own experiences with keeping psoriasis under control with diet.