Are Acorns Dangerous Nuts?

We have been having a lot of fun this fall doing Outdoor Skills programs for visiting classes.  We teach them how to identify some “dangerous plants” (poison ivy, wood nettle), how to make cordage (a very useful skill if you are ever on your own in the wild), how to build a debris shelter, how to tie basic knots, etc.  It’s not all serious, though – we also teach them how to make spinning tops from acorns, how to use an acorn cap as an emergency whistle, and how to make toy ducks from cattail leaves.  Last week, a parent asked if having the children handling acorns, even putting them up to their mouths, wasn’t dangerous, because, after all, they are nuts.  What if the child had a nut allergy? 

I didn’t have an answer. 

And what about all the walnuts and hickory nuts that are all over the ground this time of year?  I needed to do some research, and here is what I found out.

As most of us know, peanuts are not real nuts, they are legumes, so peanut allergies are not really relevant when it comes to dealing with the native nuts we have here.  However, walnuts and hickory nuts are on the list of dangerous nuts for those who suffer from tree nut allergies.  Acorns are not on any lists, and from everything I have found, they are not problematic (they have a different type of protein than the other tree nuts, which is apparently what makes them safe).  But even if they were problematic, here is the thing:  one has to actually consume these nuts in order to have a reaction to them (  Rest assured, parents:  we do not allow students to taste things here.

So, I’m breathing easier now that I know we can continue doing acorn cap whistles and making acorn tops.  But what about the walnuts and hickory nuts that are rolling about underfoot – should one be concerned about children touching them, or inhaling crushed bits of them?  Here is what is written on the American Academy of Allergy Asthma and Immunology website (

Your question is focusing on contact sensitivity or inhaled exposure in an individual who is tree nut allergic. Although it is difficult to make absolute statements, I am convinced by the available literature and clinical experience that there is no significant risk associated with a tree nut allergic person engaging in activities in close proximity to a tree, even with nuts on the ground around the tree. Certainly skin contact with nuts outside of the shell is a potential risk if common sense measures of avoidance are not in play. Although aerosol food allergen exposure has been described, this has been primarily in cooking of the food. I have cared for a patient who would have respiratory symptoms when sitting in an establishment with peanut shells on the floor, so aerosol exposure is theoretically possible but is not a realistic concern in an outside environment.

In summary, there is risk in any activity of life. I think you can reassure your patient and their family that the risk of playing under a pecan or walnut tree is negligible, even with pecan or walnut allergy, as long as the nuts are not handled or eaten. Inhalation risk is not a concern in this circumstance.

In summary, it looks like we will now caution parents, teachers and students not to handle the nuts if they have known tree nut allergies…at least if the nuts are outside of their shells.  Fortunately, most of the nuts we find are still in their shells, which is a relief considering how many times in the last few weeks we have turned around to find students with their pockets bulging with nuts they have picked up to take home!