SLIT

SLIT is an acronymn that stands for Sublingual Immunotherapy. Taking substances under the tongue or sublingually, "[D]iffuses through the mucous membranes beneath your tongue. And because of the plethora of capillaries there, the medicine has a fairly direct route into your bloodstream," according to Thomas P. Connelly, DDS. 

Normally the therapy involves giving the food allergic person a small droplet or part of the allergen under the tongue.  For example, the droplet may be 1/100th of a drop of milk or 1/100th of a peanut.  Some prepared droplets can be ordered off the Internet that contain mixtures of various types of allergens, such as egg and dairy in a variety of forms including milk, yogurt and cheese for example. 

As the patient takes regular doses of the prepared drops, gradually--over a period of months--the amount given can be increased.  Eventually the concentration level of the allergen can be increased, but with dropping back down to a small amount at first, then working up to more if no evidence of any symptoms appear.  Gradually, the hope is that the person's body become slowly desensitized to the allergen through a regular, measured dosing--not an accidental nor occasional high amount of the allergen.   

If you are patient and work under medical advice, it might be just the ticket.