Multiple allergy

My daughter for several decades has suffered from multiple allergies and intolerences. She has
severe ones such as nut and cats. she is intolerant to all fresh fruit and vegetables( can eat cooked-denatures enzymes), some dogs and most small fur animals. she also has asthma and as at tot had( now rarely) very bad eczema. As the years go by, these increase. Her peanut allergy is now airborne and many of her other allergies/intolerences are contact and eaten reaction.
We have been together to many specialists, have tried different eating styles. it seems there is no answers from anyone. I am aware that there is a private clinic in London that does desensitisation. when I looked into this it was staggeringly expensive and I think more appropriate for a person with one allergy, not potentially maybe 100 if you added nuts,fruit, veg and animals.
I don’t know what my question is to this forum but if there is anyone else that is in this situation and they have any tweaks to their life that help them. I would be interested to know.

Hi, I’ve had a vaguely similar but probably not so severe experience. The results of my insensitivities began to manifest circa pubity (not uncommon as the body goes through signifcant change) and progressively got worse until almost two decades later I just had to find some alternative to the ‘poor’ outcomes I had from NHS interventions. It began with severe seasonal rhinitis (hay-fever) - headaches, runny nose, itchy eyes, mild asthma for which the NHS gave me jabs that made things worse. 15? years later I was continually suffering migraine, severe infected sinusitus, difficulty breathing and more.
A work colleague claimed to have had a ‘miracle’ cure, of different issues the NHS couldn’t heplp, following consultation with a qualified doctor who was into alternative therapies. I was very sceptical but after much cajolling eventually made an appointment - I’ve never regretted that as it mad an enormous difference to my life (and of those that had to suffer me). It cost, yes but I consider it to have been very good value, what price do you put on quality of life.
The consultant doctor argued that most people have some intolarance to a range of substances, and that if the controllable one are reduced or eliminated the bodies immune system is the better able to cope with the sensitivities/allergens that cannot be easily controlled.
I am able to manage my issues with strict dietary exclusions. In my case refined sugars (no sucrose, no alcohol and others) dairy products, corn (including corn fed meats) and many other common foodstuffs. My issues havn’t disappeared, but they are very significantly reduced and to a degree can be controlled.
You mention changing eating patterns. How rigorous were those changes. How long did you persist with those changes before deciding there was no advantage?
I’ll happily discuss this further if you think there might be any value.
Regards