very very sorry for your difficulties.
I am been in support groups with many difficult to diagnose folks.
Never underestimate the power of time to help solve problems.
Research, more research, second opinions, trying various things.
In my experience with very I'll folks, that process just about always leads to some positive results.
I would check into a few things in addition to everything else.
Allergies to laundry detergent (thus sheets and pillowcases, and of course clothes).
Allergies to soaps, shampoos, and all beauty products.
Food allergies.
Make sure your hydration is optimal. Make sure you are truly getting those 8 glasses of water daily. Without optimal hydration it is hard to heal from any illness.
Make sure your sleep is optimal. When we are ill, so incredibly important to get those 8 hours of sleep and every single night. That is key to supporting the immune system.
And, of course, eating very health food (but cleared re food allergies)
Sudden onset, and powerful allergy to pets.
Check for environmental factors. Mold in the home...too many chemicals in the air (near a major factory or fracking), too many chemicals in the water. Chemical exposure at your job.
I would think about also joining some support groups for chronic illnesses, invisible illnesses. And see if you can connect with someone with similar symptoms.
It is the internet and hard to glean accurate info. What I would do is see if I can find, say, 5 people who agree with an idea. And then a physician or two to also agree. And then I would know that I am likely headed down a right path.
I do know a weirder factoid re skin issues. And this is very anecdotal, so I would get some confirmation before proceeding.
But I do know a number of folks who had skin issues...went down to the beach for a week...hung out on the beach, breathing sea air for a week....and skin issues just went away.
My wife's old hairdresser had horrible asthma. Moved from New Jersey to North Carolina and asthma simply went away. No longer needed his inhaler.
Wish I knew more precisely how to help.
Do take care now.
I agree with everything you have posted. I would also recommend that they see a holistic physician that provides natural Medicine/vitamins to help heal her immune system.
I have multiple Environmental and food, allergies (35 food allergies), Epilepsy, asthma, leaky, gut, fragile bones due to high doses of steroids and chemotherapy as a child for 10 1/2 years. My holistic physician has helped me more in the last 2 months that any MD has!