In June 1906 Alfred T. Schofield met a boy that was 13 years old, he had a severe reaction to eggs. He started treatment for the boy in December giving him 1/10,000th of an egg daily with a little calcium lactate. In January he increased the dosage to 1/1,000th of an egg which was taken daily without any noticeable adverse effects. In February pills with cooked and raw eggs were taken alternately with a dosage of 1/500th of an egg and the calcium lactate was discontinued. In March the amount was steadily increased till 1/75th of an egg. By June it was raised to 1/33rd he also ate a whole egg for the first time in his life. For July the pills were dropped and the boy was given pudding and cake as a test in which he was told contained egg but did not. After that he had egg in his food constantly he also had 1/6 th of an egg daily for July. Schofield concluded that patient tolerance may be established in the case of the most poisonous foods.
Prior to this and even until recent history it was standard in the case of food allergies was to avoid allergens. This was because it prevented allergic reactions and because avoidance could lead to the resolution of food allergies according to Gideon Lack. There was an extended period where food allergy testing has. stopped or at least paused because of the risk of anaphylaxis. Anaphylaxis is a serious life threatening allergic reaction.