I only became aware of my issue with tree nuts after eliminating wheat and milk from my diet. So I do not know when I started to have these allergies. They are considered a more common adult allergy but for what it’s worth I did find chestnut to be addictive since childhood. And based on symptoms, chestnut and possibly pecan were the only ones I thought might actually be a true IgE allergy. I tested positive to pecan but chestnut was not available for testing.
Reaction patterns and sensitivity and severity are all over the map depending on which nut and in what form it is consumed.
Compared to whole nuts, nut milks have much less solids. Most commercial almond milk contains very little protein. It seems my sensitivity level is such that for some nuts I tolerate a small amount of nut milk. Also in my case raw nuts cause a more instant reaction than the same nut roasted.
With roasted chestnut there was no immediate reaction but migraine after exercise, all over itchiness, and later acne. But a small bite of raw chestnut caused immediate abdominal pain and itchiness all over.
With pecan, I only had a small taste of pecan milk, which was enough to cause an instant headache. The swiftness of this was alarming. So I’ve never tried more than this amount. And this was repeated a few days later with just a lick of pecan milk.
Hazelnut milk caused a pretty immediate sore bloated pressure feeling in the stomach but no other obvious symptom. But when I ate the solids left over from making the nut milk (one bite of a cookie made with the remaining hazelnut meal) I had another shock, vomiting, and diarrhea episode.
After severe reaction to hazelnut, milder suspicious issues with almond, macadamia nut and pistachio, I decided perhaps it was not worth the risk to test every tree nut out there. So for the time being I am avoiding all tree nuts except coconut (but is this technically a tree nut? Some classify it as a fruit).
In general tree nut cross reactivity patterns tend to cluster into two related groups: (pecan, walnut) and (almond, cashew, pistachio) with hazelnut potentially appearing in either group.
My tree nut symptoms also cluster into two groups.
Wheat-like reactions (headache, itchiness): pecan, chestnut, macadamia nut?, (walnut? haven’t tried due to its close relation to pecan)
Milk-like reactions (FPIES/ diarrhea): hazelnut, almond, cashew
Highly suspicious of juniper berries (unlike the name, this is similar to pine nut found sometimes in carnitas, other foods?) also causing gastrointestinal trouble (mild milk-like reaction).