Food Allergies - Contact Reactions

When AIDS first captured the headlines, mobs of the irrational and uninformed gave their fears free reign. They imagined the worst possible scenarios — their children catching AIDS by sharing a desk with a fellow student who had AIDS, the possibility of passing AIDS through a handshake or a hug, mosquitoes carrying the AIDS virus over the neighbor’s fence.

None of that happened, but the fears whipped many people and even entire communities into a frenzy. Although everybody knows that you can’t catch an allergy from someone else, uninformed food allergy sufferers and uninformed parents of children who have food allergies occasionally develop similar overblown fears, often quite justifiably.

They may read an article written by an ill-informed writer, hear a rumor, or let their imaginations run wild because they know first hand how serious a reaction can be. In any event, most of the fears and concerns over contact reactions are overblown.

Contact reactions occur when a problem food touches the skin. Common examples of this include having milk spilled on you, being touched by someone who has peanut butter on his hands, or being kissed by someone who has just eaten eggs (something that’s not all that pleasant even if you don’t have an egg allergy).

Predicting the severity of a contact reaction Although contact reactions are very common, they’re generally much less severe than reactions you experience when you eat an offending food. Contact reactions are also typically localized to the site of the contact; that is, the allergen doesn’t get into your system and trigger a full-body response.

Contact reactions, however, can be more serious, depending on the amount of contact and on the location of contact — the body part that comes in contact with the allergen. Following are descriptions of three scenarios in which the contact reaction may be more severe:

  • Significant exposure: Having a few drops of milk splashed on you typically results in mild reaction, if any. If you (or some clumsy ox) spills a glass of milk on you, that may cause a more severe reaction.
  • Contact with the eyes: Your eyes are more than a gateway to your soul. They can be a gateway to allergens, as well. Your eyes are one of your most sensitive body parts, and even a little allergen can cause major swelling. Your eyes can even absorb allergens, which is almost like eating the food, because the allergen can travel systemically (throughout your entire body).
  • Hand contact to mouth ingestion: If your hands come in contact with an allergen and then you put your hands to your mouth or touch some nonallergenic food you’re eating, the contact reaction can turn into an ingestion reaction. This scenario causes additional concern in relation to young children who may be less aware of their surroundings and more prone to putting their hands in their mouths.
  • Mouth to mouth ingestion: Kissing someone who has recently eaten a food you’re allergic to can cause a reaction, sometimes severe. By following a few simple precautions, you can virtually eliminate this risk. I'll provide some safe-kissing tips for teenagers later.

Thankfully, although these three scenarios engender tons of worry, none of them are at all common.

If we let our imaginations run wild, we can think of innumerable ways in which contact reactions might occur. Just think of a day at school and imagine that a few children walk into school with peanut butter all over their hands. As the pass through the school, they might leave a deadly trail of peanut on door knobs, drinking fountains, library books, art supplies, computer keyboards, basketballs . . . even the monkey bars!

What, though, is the real risk? The answer is that the likelihood of these incidental contact exposures actually leading to a reaction is extremely small. I care for thousands of patients with food allergy and have dealt with tens of thousands of reactions. Of all the reactions I’ve witnessed, I can count on one hand the number that we could trace back to this sort of hidden, unsuspected exposure.

I’ve cared for many families who ultimately decided to home school their children specifically over fear of potential contact reactions. I have seen children become so paranoid that they won’t hold hands with another child or even touch a door knob. While sensible precautions are warranted, remain rational and keep your imagination in check, for your own good as well as the good of those under your care.

Follow these sensible precautions to allay your concerns:

  • Remain aware of your environment and of any potential hazards without becoming obsessed over them.
  • Pay attention to major exposures, and let the little stuff go.
  • Keep your hands clean and out of your mouth.
  • Be careful kissing. A peck on the cheek is fine, but kissing on the lips is riskier.
  • Wipe down tables before meals. My colleagues and I have shown in our research that peanut protein can be cleaned from hands and tables with soap and water, as well as most types of wipes.

Don’t let the myriad of possible contact exposures run (and ruin) your life or foster irrational fears in a child.