Do you know of any desensitization treatment for my son (turning 5 years old in December) who has a fatal allergy to nuts (peanuts and all types of nuts)? I heard there is one originated in Denver, Colorado, but our specialist in Toronto (Hospital for Sick Children) would not suggest such a treatment for anyone below 16 years of age due to the treatment's recent nature and lack of established results. Does this mean we will continue to have a Damocles' sword hanging over us and our lives forever?

A five-year-old child eats every few hours to take in the fuel that he needs for energy, growth, and bodily repair. Usually, eating is both fun and helpful. Sometimes, it is deadly.

Some individuals have reactions to particular foods. These reactions can range from mild intolerance to fatal allergies. Most of the children who develop life threatening food allergies either have asthma or a family history of asthma, eczema, or hay fever. Most of them have mild to moderate reactions (rash, wheezing, tingling, diarrhea, etc.) to the offending food before the allergy becomes severe. In a few children, the first time they eat the particular food, they become sensitized and the second time they eat even a miniscule amount of that food, an explosive reaction occurs.

Life-threatening food allergies (most commonly to nuts, peanuts, or shellfish) can kill children in two ways. The first is called laryngospasm. As the food is swallowed, it produces immediate swelling that spreads to the vocal cords. If the vocal cords swell shut, the child is unable to breathe and dies with terrifying rapidity. The second mechanism is called anaphylactic shock. The child swallows and digests the food and, as long as two hours later, goes into shock and dies.

Children with life-threatening food allergies do not grow out of them. Without treatment, these are lifelong conditions.

For some types of allergies, a process called desensitization is effective. Desensitization involves administering very small amounts of the allergy-producing substance to the child, in the hopes of allowing the body to adjust and blunt its response to this substance. "Allergy shots" are an attempt to desensitize, or at least hypo-sensitize, someone who is allergic. Until recently, desensitization has never been shown to be effective in any food allergy.

Because desensitization has helped some children with anaphylactic reactions to bee stings, many allergists have wondered whether this process might help children with life-threatening allergies to tree nuts or peanuts. The allergic reactions are even more explosive whenever the offending substance is injected rather than eaten, thus such an attempt would be quite dangerous. If it worked, however, it would be a great boon, since these children are already at such high risk.

In 1996, a brave physician, Harold Nelson, M.D. at the National Jewish Center for Immunology and Respiratory Diseases in Denver, Colorado, launched a heroic study of peanut desensitization. This study was extremely well designed and carefully administered. It was a controlled study in which some children were injected with peanut extract and some were injected with a placebo. The injections were only given with full intensive care unit and emergency department support. It is difficult to imagine a safer place to conduct this study than in this world-renowned center, with people who have great respect for the power of allergies. Still, one child who received the peanut injection died seconds later from laryngospasm, before resuscitation was possible.