QUESTION:

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?

Sonny Jose Mississauga, Ontario, Canada

DR. ALAN GREENE:

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.

We used to think that children with life-threatening food allergies do not grow out of them. Now we know that some do, even without treatment.

For some types of allergies, a process called desensitization is effective to reduce allergies. 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. This tragedy abruptly ended the only study conducted on desensitization to peanut allergies.

Afterwards, the code was broken so that researchers knew which children had received the placebo and which had received the peanut extract. The preliminary data indicated that, overall, the children who had received peanut extract were somewhat less sensitive to peanut allergies than they were at the beginning. I spoke with allergist Andrew Engler, M.D. who emphasized that at present this information is only of theoretic use.

Life-threatening allergies to tree nuts and peanuts can be lifelong conditions. Before embarking on the arduous treatment for these conditions, it is important that the diagnosis is clear. I spoke with allergist Steven Machtinger, M.D., who related the story of a boy who had an anaphylactic reaction after eating a Butterfingers candy bar. It was initially assumed that he had a life-threatening allergy to some type of nut. A diagnostic blood test, called an RAST test, revealed no nut allergy. This was followed by skin testing which likewise revealed no nut allergy. Be certain of the diagnosis, because the treatment is difficult.

The core of treatment is absolute and complete lifelong avoidance of all nuts and peanuts in any form. This includes nut oils and nut butters. Most intake of nut products by people with known nut allergies occurs when the nuts are present as a hidden ingredient, perhaps in a cake, a cup cake, or even chili. One young man ordered a chocolate chip cookie with no nuts at a nationally known cookie store. On his first bite, he recognized it as a peanut butter chocolate chip cookie. This wasn't soon enough -- moments later a full-scale resuscitation was underway. He left the cookie store on a ventilator. Thankfully he survived.

No matter how careful you are, it is almost inevitable that it will happen -- your son will eat nuts. I say this now in hopes that when it happens, you will remember my thoughts and see yourselves with the same compassion that I feel for you at this moment -- not with guilt or judgment. I also tell you this so you will take the second phase of treatment seriously. You must be prepared to deal with the emergency when it happens.

Learn CPR. Now.

Your child will need an injectable epinephrine kit (such as EpiPen or Twinject) -- make that two kits. Injectable epinephrine is the one drug that can stop this reaction in its tracks. You and your wife should each carry an epinephrine kit with you at all times, 24 hours a day. It is important that each of you is comfortable using it. If you think there has been a nut ingestion, USE IT! Don't wait and see. Use the epinephrine kit and take your child to the emergency room immediately.

Teach others what to do

Once you have educated yourself on emergency care, it is vital that you educate any other adult who will be caring for your child. These adults should know CPR and should have an injectable epinephrine kit. In a chilling study from Johns Hopkins University, 13 children with life-threatening nut allergies were followed -- 6 of them died. All 6 of these children had ingested nuts while at their various schools. They immediately went to their school nurses, who told them to lie down and see if they felt better. Each of them did feel better and went back to class -- and died. Speak with your child's teachers, principal, and school nurse -- in person. Any adult taking care of your child should be given a written note that indicates your son has a life-threatening allergy to nuts and peanuts in all forms.

Find support

Don't go down this road alone. It sounds like you have a knowledgeable allergist. Good. You will also benefit from links to other families going through the same thing. Food allergy support groups are available in many locations. Whether or not you contact a local support group, I would definitely contact and join The Food Allergy and Anaphylaxis Network (FAAN). It costs about $30 per year and provides outstanding information, literature, videos, and the kinds of practical information and support you will need. Their phone number is 703.691.2713 or 800.929.4040. Their address is 11781 Lee Jackson Hwy, Suite 160, Fairfax, Virginia 22030-3309. Contact them right away. They also have programs for schools and camps.

Some of the research being done right now in life-threatening food allergies is very exciting. Companies like Genentech, based near San Francisco, California, are working on products to block this type of allergic response at the cellular and molecular level. This research is quite promising, but still only investigational.

Life-threatening food allergies are not rare. As deadly and as common as they are, very few children actually die from them. With this combination of avoidance, preparation, and education, your five-year-old can look forward to a long and healthy life.

Alan Greene, M.D. earned a Bachelor's degree from Princeton University and graduated from medical school at University of California at San Francisco. Upon completion of his pediatric residency program at Children's Hospital Medical Center of Northern California in 1993, he served as Chief Resident. During his Chief year, Dr. Greene passed the pediatric boards in the top 5 percent of the nation.

Dr. Greene entered primary care pediatrics in January 1993. He is on the Clinical Faculty at Stanford University School of Medicine where he sees patients and teaches Residents. He serves as the Chief Medical Officer of A.D.A.M., Inc., a leading provider of consumer health information, and helps direct A.D.AM.'s editorial process. As A.D.A.M.'s CMO, he served as a founding member of Hi-Ethics (Health Internet Ethics) and helped URAC develop its standards for eHealth accreditation. He is also the Founder & CEO of DrGreene.com. Dr. Greene was also named Intel's Internet Health Hero for children's health. He is an author, medical expert, and a media personality.

Dr. Greene is the author of Raising Baby Green (Wiley Books, 2007), From First Kicks to First Steps (McGraw-Hill, 2004), and The Parent's Complete Guide to Ear Infections (Avon Books, 1997). He is also a co-author of the A.D.A.M. Illustrated Family Health Guide (A.D.A.M., Inc., 2004). Dr. Greene has appeared in numerous publications including the Wall Street Journal, Parenting, Parent, Child, American Baby, Baby Talk, Working Mother, Better Home's & Gardens, and Reader's Digest. He also appears frequently on television and radio shows as a medical expert.