I believe that treating natural remedies with the same viewpoint as pharmaceuticals does not give you a very high rate of success. Treating symptoms without dealing with the root cause can improve life in the short term but with not heal the whole. When using pharmaceuticals there will almost certainly be other problems down the road, when using natural cures their effectiveness can wear off in time. I believe what science is now starting to discover, that the root cause for a lot of allergies is a lack of balance and amount of good bacteria in our bodies and particularly in our gut. Never before have human beings been in so much daily contact with a myriad of low level toxins that kill bacteria and brain cells, never before have we eaten a diet so devoid of life.
I think every bodies cure is site specific (permaculture thumbs up!). You should make sure you are eating lots of live foods, fermented and raw vegetables, raw milk and stinky cheeses, raw honey kombucha, cider vinegar, are some of the best. You should look into really powerful pro-biotics, from really reputable company's like Get Real Nutrition (all the products grown on a permaculture farm btw). Look into mushrooms for immune support ( Fungi Perfecti, is another company practicing permaculture). By all means try nettle and other recommended herbs to see if they offer immediate relief, pay attention to your body and how it reacts to things ( use the feedback loop!). We have been conditioned by our culture of separation to think that we need to ask someone else how to fix our bodies even though we are the ones inhabiting them.
For what it's worth since it is by no means a controlled study my family of 5 suffers from zero allergies, my children are the only kids in their class at school to be allergy free and they have never suffered from ear infections, they have been drinking raw milk and Kombucha since they were born and eat kimchee and dirt on the regular.
I really hope you find the answer you are looking for so you can enjoy a life around nature.