Peanut-Allergic Teen Dies After Kissing Boyfriend
   
  By Katrina Woznicki, MedPage Today Staff Writer
Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University of Pennsylvania School of Medicine.
November 30, 2005
Also covered by: BBC News, CNN, Hartford Courant, New York Daily News 
 

MedPage Today Action Points

Note that teenagers with food allergies are a particularly high-risk group to severe allergic reactions. They are less likely to take precautions to reduce their risks and are less likely to be prepared when a reaction occurs.

Encourage allergic patients with a history of severe reactions to carry a self-administered epinephrine injection device.
 

Review
SAGUENAY, Quebec, Nov. 30 - A 15-year-old girl exquisitely sensitive to peanuts died after kissing her boyfriend who had eaten a peanut butter snack hours earlier.

Christina Desforges died a week ago at Chicoutimi Hospital here 155 miles north of Quebec City, several days after a severe reaction to the kiss from her boyfriend. According to published reports, Desforges had been immediately treated with a shot of adrenaline. The hospital declined to offer any further details.

The so-called death kiss drew a great deal of media attention, but kissing, it emerged, is a surprisingly common way for teenagers with severe peanut allergies to experience a reaction they didn't expect, noted several authorities. Usually, though, the allergic reactions are mild.

Teens are a particularly vulnerable group, said Anne Munoz-Furlong, founder and chief executive officer of The Food Allergy & Anaphylaxis Network, a Fairfax, Va.-based advocacy organization.

"The highest risk group for a fatal reaction is teenagers," she said. That's because teens are engaging in activities with their friends independently of watchful parents, they are less likely to be prepared for an allergic reaction, and they're also less likely to have a self-administered epinephrine injection device handy in case of an emergency.

A letter in the June 6, 2002, issue of The New England Journal of Medicine found that kissing as a route of allergen exposure wasn't as infrequent as one might have suspected.

In the letter, Rosemary Hallett, M.D., an allergist at the University of California at Davis, and colleagues reported that 5.3% of their 379 patients who had allergies to various nuts experienced allergic reactions after kissing another person. Most of the reactions were mild, the authors said, however four patients reported bronchospasms and one child had a life-threatening reaction. Four patients also reported allergic reactions even after their partners had brushed their teeth.

"Since one third of our subjects had reactions while dating, teenagers and young adults in particular need to be informed about this mode of exposure to allergens," the authors concluded. "Patients of dating age who have severe food allergies may need extra encouragement to tell friends about it."

Reactions to peanut allergy can include swelling and hives and lead to anaphylactic shock. Mark Dykewicz, M.D., director of the allergy and immunology training program at St. Louis University, said it doesn't take much to trigger a reaction this severe.

"As little as a hundred micrograms of peanuts can provoke a reaction," Dr. Dykewicz said. "Kissing is a known way of inducing these sorts of reactions. It really dovetails with the fact that very small amounts of peanut protein allergen are capable of inducing reactions. The antigen is a very potent immune system stimulator."

There appears to be an increase in the prevalence of peanut allergies among children and adolescents, said Dr. Dykewicz, but why it's rising remains unknown. Individuals typically outgrow sensitivities to food allergens such as milk, eggs, and soybeans, but usually not to peanuts. It's only 20% likely that children will outgrow a peanut allergy, and if they do outgrow it, the allergy can eventually recur.

According to a Duke University review published in the December 2005 issue of Current Opinion in Allergy and Clinical Immunology, food allergy affects up to 6% of all children in the U.S. and up to 4% of all adults. Peanut is the most common allergen for children over the age of three. Peanut allergy, one of the most common food allergies, "can be devastating," the Duke researchers wrote, "as reactions range from urticaria to severe anaphylactic shock and death."

"Peanut reactions are somewhat unpredictable," said allergist Philip E. Gallagher, M.D., of Erie, Pa., a fellow of the American Academy of Allergy, Asthma, and Immunology. "There are people who have severe reactions one time and hardly have any reaction the next time."

Doctors don't know why peanut allergic reactions are so varied, Dr. Gallagher said, but what is known is that there appears to be a dose-related response between the level of exposure and the reaction. For patients who are highly sensitive to peanuts, the best protection is complete avoidance of peanuts, but that can be challenging for patients and clinicians alike.

The quickest and most risky route of exposure is oral and gastrointestinal ingestion followed by inhalation and then topical, said Dr. Dykewicz. "Topical is probably not going to give you the load of allergen to give you sensitization, but once you've got sensitization, contact with the skin might cause problems in some people."

Even if patients minimize their peanut exposures in their own immediate environment, it becomes a challenge to control their risks of exposure with people they interact with.

Controlling allergen exposure remains a challenge for many patients. Drs. Dykewicz and Gallagher both mentioned cases of women who had penicillin allergies and experienced reactions after having sex with partners who were taking penicillin.

Cases like this one from Quebec highlight the importance of avoiding allergen exposure, the experts agreed, but there will always be risks.

"Can you anticipate every possible exposure," Dr. Gallagher said, "and protect your patients from harm and I guess the answer would be that's very difficult to do."

Patients should be provided with a self-administered epinephrine injection device for use when they are inadvertently re-exposed to the offending agent. Patients who are at risk for anaphylaxis should also wear a Medic Alert bracelet or similar device at all times.

Primary source: The New England of Journal of Medicine
Source reference:
Hallett et al, "Food Allergies and Kissing," NEJM, June 6, 2002; vol. 346, No. 23, p.1833-1834

Additional source: Current Opinion of Allergy and Clinical Immunology
Source reference:
Pons et al, "Towards immunotherapy for peanut allergy," Curr Opin Allergy Clin Immunol Dec 2005; vol. 6, p.558-562

http://www.medpagetoday.com/AllergyImmunology/Allergy/tb/2241