Food Allergies and the Perfect Kiss

Food Allergies and the Perfect Kiss

For most of us, kissing, whether passionate, loving, or friendly, is usually a spontaneous demonstration of affection. But for those living with food allergies, this is a gesture that must be carefully planned. Believe it or not, the contact associated with a kiss may be enough to cause a severe allergic reaction!

In recent years, several cases of allergic reactions triggered by kissing have been reported in literature [1, 2]. It seems to be a relatively common phenomenon, and it seems to be the trend emerging from analyses carried out by Rosemary Hallett and her associates. After analyzing the files of 379 individuals allergic to peanuts and nuts, it showed that 20 of them (5.3 %) associated the onset of their allergic reaction with kissing another person [3]. But how is this possible?

Allergens that linger in the mouth…

In 2006, Jennifer Maloney and her colleagues wanted to know if traces of peanut could be detected in the mouths of those who had consumed them [4]. They measured the amount of Ara h 1 (one of the allergenic proteins in peanuts) in the saliva of 38 individuals who had eaten peanut butter. They observed that the amount of Ara h1 in the participants’ saliva varied greatly: 0.014 – 34.9 mg/ml, 5 minutes after consumption. It also decreased significantly over time. However, it is important to note that when it was measured again more than 60 minutes after consumption, it was still detected in the saliva of nearly 10% of the participants.

The authors then wanted to know whether the amounts of Ara h 1 measured in the study presented a risk to people with food allergies. They estimated that about 5 ml of saliva is exchanged between two individuals during a so-called “passionate” kiss; the authors then estimated that someone who is allergic to peanuts could come into contact with about 37 mg of peanut protein during such a kiss. According to them, this amount corresponds to 1/10 – 1/5 of a peanut [4]. Since a mere trace of an allergen can trigger an allergic reaction, these findings invite all those living with allergies to be cautious. It should be noted, however, that further studies are needed to confirm these findings and to extrapolate the results to other allergens.

Precautions for safe kissing

The important thing to keep in mind with respect to the studies mentioned in the previous section is that the risk is real; an allergic reaction is possible when one person comes into contact with another person’s saliva, whether it be through kissing or sharing utensils.

In an ideal world, the partner of someone living with allergies should avoid eating allergenic foods. However, studies show that there are ways to reduce the amount of allergens in saliva: by brushing your teeth, rinsing your mouth, or chewing gum. Yet don’t forget that these methods do not guarantee the complete elimination of allergens in saliva [4].

Therefore, if you live with food allergies, be mindful that a kiss can cause an allergic reaction and be sure to let your partner know.  Unfortunately, there is no such thing as zero risk when it comes to food allergies. But remember, the more we talk about food allergies and share information with others, the more our society will be prepared and ready to handle it. This will make life a lot easier for those who are faced with this challenge on a daily basis.

[1] Wutherich B et al. Kiss-induced allergy to peanut. Allergy, 2001, 56:913.

[2] Eriksson NE et al. The hazards of kissing when you are food allergic. A survey on the occurrence of kiss-induced allergic reactions among 1139 patients with self-reported food hypersensitivity. J Investig Allergol Clin Immunol, 2003;13(3):149-54.

[3] Hallett R et al. Food allergies and kissing. N Engl J Med, June 6, 2002;346(23):1833-4.