Yes, but... There are still hazards. The most likely to work at this time is a food desensitization, in which gradually increasing amounts of food is ingested over a few days. There is a risk of a severe allergic reaction, and once completed, small amounts of that food need to be eaten daily. Other treatments are in the works, but are still a few years off.
Yes. Currently, several products are under investigation. All follow the principles of desensitization; starting with very small amounts, the patient is repeatedly exposed to the food substance. Over time the body may develop tolerance. It is still unclear if desensitization will permanently "cure" the food allergy or if it will return. Warning: do not try this at home - there is significant risk.
Perhaps. Oral desensitization is an investigational approach under study at duke, stanford & other research institutions in the us & europe. A drug therapy based on a combination of two chinese herbs (yes, drugs come from herbs) is under study at mt. Sinai school of medicine. Both approaches are "on-the-way". Neither has yet arrived. It's hard to be patient. Watch out for charlatans and scams.