The very short answer of how the break the cycle of developing more allergies and heal old allergies...heal the digestive system: the gut, the bugs (bacteria & yeast), the immune system (75% of the immune system is in the gut/intestines).
The Gut. It's very possible that there is an issue with leaky gut. Where "holes" in the intestinal wall allow large food particles into the blood, where the immune system sees them as invaders (virus, bacteria, or toxin)and attacks, because big things in the blood are virus, bacteria, or toxin, nutrients from food in the blood are suppose to be small. The immune system then says hey, remember that substance for next time and we can conquer it more quickly = allergy reaction the next time the food is eaten. An explanation on healing the gut is in the next section on Bugs.
The Bugs. We all have an inner ecosystem - good and bad bugs in our digestive system. It's not that some are really bad, we need them, we just need them IN BALANCE. Too many of one type becomes a bad bug and can cause lots of problems. The most common culprit: candida, or yeast. It is their job to eat large food particles so they don't get into the bloodstream. Lots of large food particles, means more and more yeast are needed, but in the course of doing their job, they can multiply out of control and actually grow into and through our intestinal wall and get into the bloodstream themselves, and into our other organs, etc when they should only be in our gut and in the right proportion to other bugs there. If this is the cause...digestive enzymes to help digest the food are needed to correct the original reason the yeast overgrew in the first place. Yeast can also overgrow because the good bacteria are killed off for some reason. Things like birth control pills, hormone imbalances, acne medication, and ANTIBIOTICS all can cause yeast to get out of control. (Antibiotics - Think about it "anti" "biotic" or "against life". I'm not saying antibiotics are bad, I'm just saying we need to be aware that they kill both bad AND good bacteria and if we must take antibiotics, to make sure we take probiotics as well to help recolonize our gut with good bacteria after being on antibiotics. Personally, I try to find all-natural antibiotics in the form of herbs, essential oils, and things that help our bodies fight the bugs (thereby strengthening the immune system long term) rather than go in and wipe them out with drugs (which used repeatedly, in the long run weakens the immune system because it gets no exercise or experience).
It can be tough at first, but in the long run it sure pays off. My boys used to catch every little thing going around, and Jordan would be sick and completely miserable for 2-3 weeks every time he caught something. Now that I've been using natural things and have been working to build his immune system (for him that meant keeping him away from other sick kids for about a year - when you're sick, it's hard to heal other chronic issues and strengthen the body & immune system). Last week and this week we've been around hacking coughing kids many times and neither of my boys have gotten sick! It's wonderful!! FYI: it also means limiting (or eliminating) sugar. Sugar significantly depresses the immune system for 5-6 hours after it is eaten.
If there is already an issue with yeast, due to partially digested food, antibiotic, or other medication use. Then it needs to be killed and brought back under control. There are many ways to do this. One of my favorites is by using enzymes and probiotics, another is a combination of anti-fungal herbs in a product by Pure Herbs called Can Sol. FYI: yeast feed on sugar and anything the body can readily turn to sugar: wheat, corn, pasta, potatos, dairy, maple syrup, etc. While combating yeast it may be necessary to seriously cut back (or completely eliminate) the intake of these foods for several weeks.
Once the yeast is controlled and the gut bacteria balanced, the gut will start to heal. There are things to help accelerate the healing of the gut as well. We've used L-glutamine, also knitbone or comfrey.
The Immune System. This is multifaceted and involved. To be completely honest I don't totally understand this area yet. What I do know is that immune system disregulation is epidemic today, with Th1 and Th2 responses being imbalanced. Th2 is overactive in many, many children (just think asthma & allergies). This means the immune system is always on high alert, fighting, everything. How did this flip happen? Well, it's not the only reason, but the most common answer for that is: vaccinations.
So, the immune system. That bring us back to the basis of recovery from many things (including: asthma, ADD, allergies, autism spectrum):
1)Stop putting bad things in
2)Put only the best things in as possible (food, body products, scents)
3)Get the bad stuff that is still in the body out.
For more information on this check out the pages about causes and treatment, toxicity, and nutrition.
While Working on the Gut, Bugs, and Immune System. If the child needs a greater variety of foods, the best thing I have found to help is called NAET or BioSET. However, the effectiveness of these techniques is very dependant on the skill and knowledge of the practitioner. Try to find one that others have had success through and who won't break your bank with a gazillion treatments.
After balancing the gut bacteria, immune system, and healing the gut, it may be necessary to do a treatment of NAET or BioSET for an existing allergy/sensitivity to clear it from the system and "reset" the immune system so that it no longer reacts.
UPDATE 3-10-12: On the flip side, once all those root causes are healed the allergies very well may just disappear one by one, that's what we are finding is happening for Jordan.