<<Disclaimer: Verify this information before applying it to your situation.>>
 
>>It can be one nut, many or all
 
It would be interesting to meet someone who has allergies to all nuts.  Most
nuts are totally unrelated foods.  They have different protein structures.  Most
allergies are to a few food families, or to selected food(s) within a family.
 
Pecans are related to walnuts, butternuts, heartnuts.
 
Cashews are related to pistachios, which are related to poison sumac and ivy
(and mangoes).
 
Almonds are unrelated to any other nut.  They are a member of the rose family,
and are related to peaches, cherries, nectarines, apricots..., and, of course
rose hips.
 
Peanuts are unrelated to other nuts, as they are in the legume family (same as
soybeans).
 
Filberts stand alone.
Brazil nuts stand alone.
Pine nuts stand alone.
Chestnuts stand alone.
Beechnuts stand alone.
Coconuts are also not related to any other nuts, and less so than any of the
others.
(by "stand alone", I mean unrelated to other "nuts".  They do have other plant
relatives.
 
So, as you can see, it would be odd indeed to have a true "allergy" to such a
wide variety of unrelated foods.
 
It is just like someone who says they are allergic to all "grains".  It depends
upon how you define a "grain".  If grain means member of the grass family, fine.
If it includes buckwheat, amaranth, quiona, and other "non-grains", then I would
be suspicious, as those are just seeds of totally unrelated plants from
unrelated families.  Thankfully, nature has provided us with enough diversity
that even the entire grass family can be avoided, yet people could still get
grain-like nutrition from non-grains.
 
Joanne