He was able to find out what it was that Small Paul was eating that was eating him.  Of course, he did something else for Small Paul as well.  I am sure that you will be able to figure out what he did.

"I have found out what is wrong with your boy," said Doctor Allergy.  "Small Paul cannot eat fudge or eggplant.  If he eats fudge he will be sick.  If he eats eggplant he will be sick.  If he does not eat fudge or eggplant he will not be sick.  He will be well.  If he eats either fudge or eggplant he will be unwell.  He will not be well at all."

Doctor Allergy always made his explanations simple.  He made them simple, not for Small Paul, but for Momma Mall and Tall Paul.

"Why, that is simply silly," said Tall Paul.  "Everyone knows that in my stall in the mall I make the best fudge of all.  I have never heard anything so ridiculous in all my life."

"That is true," Doctor Allergy said patiently.  "You do make the best fudge of all and I, for one, happen to enjoy it often."

Doctor Allergy was patient with the parents of his patients, no matter how silly they seemed to be. He had discovered something that all children know. It is important to be patient with parents.  He also realized that if he lost his patience with the parents of his patients who had already lost their patience because of their child's allergy; he may end up losing his patients.

"Yes, I do," said Tall Paul.

"I know you do," said Doctor Allergy.  "You do make the best fudge of all.”  After a brief pause, he continued. "If Small Paul eats even the tiniest piece of fudge, even the teensiest sliver of the best fudge of all," he hastened to add, "Small Paul will be sick.  He will not be well at all.  It is as simple as that."

"Jellybeans," said Tall Paul.  "I guess that means I won't be able to come swinging in the back door singing, "Fudge by Tall Paul.  The best fudge in the mall."

Small Paul was especially embarrassed because Tall Paul, out of force of habit, had sung his, 'Fudge by Tall Paul, the best fudge in the mall.' ditty just as he did almost every night when he came swinging in the back door. Honestly, parents can be so embarrassing at times, thought Small Paul. 

"Yes, you can if you still want to," said Doctor Allergy.  "Small Paul will just have to realize that he can't have fudge anymore.  If he eats fudge he will not be well.  He will not be well at all."

"Not at all," echoed Small Paul.

"And remember," said Doctor Allergy, giving Small Paul a wink.  "No eggplant."

"I'll try to remember not to eat eggplant," said Small Paul winking back.

Momma Mall smelled a rat.  She did not understand why eggplant was supposed to be making Small Paul sick. She believed that you could only have allergies to foods that you liked to eat.  She did not think that you could possibly have allergy to something that you hated with a passion. What she did not know was that Doctor Allergy was in the habit of adding  on an extra allergy or two so that his patient would be happy not having to eat something that he hated to eat.  It almost made up for not being able to eat something that he loved to eat. Of course, Dr. Allergy had remembered to forget to tell Momma Mall that the eggplant allergy was a convenience allergy. Sometimes, it is best for mothers not to know everything.

After a few days with no fudge or eggplant, Small Paul began to feel well.  He went back to school, making the snow squeak under his feet and licking icicles when he felt like it.  Momma Mall was happy that her Small Paul was now well. Everyone was happy.  Everyone but Tall Paul was happy.  For some reason, Tall Paul was no longer happy.  He was not happy at all.  He was unhappy in his stall in the mall.  He was so unhappy that he did not want to make his fudge in his stall in the mall even though he knew it was the best fudge of all. The idea of making fudge did not make Tall Paul happy anymore. So, one day, he stopped making fudge and began making tofu and who can blame him?

He took down his sign in the mall that proclaimed: 

BEST FUDGE OF ALL

and put up one which said:

GOOD FOR YOU TOFU

He now called his stall in the mall:

GOOD FOR YOU TOFU

When he came home at night, he would come in the back door singing: GOOD FOR YOU TOFU