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Cleaning Residual Peanut Proteins


This week my daughter went on a field trip with her class to a museum.  Places like that always worry me, because people are allowed to bring in their own food.  You never know when some child might be walking around with a PB&J or some cheese and peanut butter crackers touching everything in site.  Anyone who deals with someone who has a peanut allergy needs to be aware of the dangers of residual peanut proteins that can be left behind anywhere that peanut butter has been – surfaces, hands, and mouths.  Peanut proteins like to hang around and are not washed away with just water alone.  Luckily, there has actually been research done to find the most effective way to clean up peanut proteins.

Hard Surfaces: If peanut butter gets on a counter, table, desk, or any other hard surface, wiping it down with a wet rag/sponge will not remove the peanut proteins from the surface.  Research shows that even washing with dish detergent left a tiny but detectable trace of peanut proteins behind, however, the amount should be low enough to not cause a reaction.  The only tried and true way of removing all detectable traces of peanut residue from the surfaces is to use a liquid cleaner that contains bleach, or disinfecting wipes, such as Lysol Wipes.  My daughter’s allergist actually wrote up a letter to her school saying their her peanut-free lunchroom table needs to be wiped down using a clean rag/sponge that is dedicated only to the peanut free table, in order to avoid cross contamination.

Hands: As far as washing hands goes, water alone does not remove peanut proteins from the skin, and neither does hand sanitizer.   The only way to effectively remove all detectable traces of peanut residue from hands is to wash with liquid/bar soap and water.  Proper hand washing techniques should be followed: Wet hands with warm or hot water, apply soap, lather well, rub hands vigorously for at least 20 seconds, scrubbing all surfaces including the backs, wrists, between your fingers, and under your nails, rinse well, and dry hands with a clean or disposable towel.  If possible, use the towel to turn off the faucet.  In case water is not accessible, wipes such as Wet One wipes and Tidy Tykes wipes also proved to be effective, but should not be used as a replacement for hand washing.

Mouths: Researchers studied participants who ate two tablespoons of peanut butter.  They then measured the peanut protein levels in their saliva for several hours.  They allowed them to rinse their mouths with water, brush their teeth, and chew gum, however none of these activities lowered the peanut protein level in their saliva to one that would not potentially cause a reaction in someone with a peanut allergy.  The only thing that did lower the peanut protein levels was eating a peanut-free meal, and waiting several hours.  Licking your lips, after eating peanut butter, and then kissing a peanut allergic person on the cheek can cause a skin reaction, while kissing them on the lips can cause an even more serious reaction, especially if they lick their lips right away.  When your child begins dating, their dates should be fully aware of the allergy ahead of time.  If their date ate something that could even be considered questionable, kissing should be completely avoided.

If a contact allergic reaction does occur, oral antihistamines such as Benadryl can reduce the level of histamine in the body, lessening the reaction. Also, topical hydrocortisone creams can also lessen the itching, redness and inflammation.


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