Seems to me that allergies are highly individual.  We on the Paleo diet
try to claim that eating Paleo is good for everyone.  That may not be
true.
There may be people that are alergic to most of the things on a
Paleo diet, and not alergic to grains. They might be better off on a
food pyramid diet.  (Yikes Blasphemy!)

Also someone
on a Paleo diet and having alergic reactions may be reacting to
something completely different.  For example, they may be cooking
on the stove more (all that meat) and the teflon in the pan is
a plastic and they react to that.  Or they could be reacting
to lighterfluid from their barbecue cooker.  Who knows?

The true proof of the suitability of any diet is what works
for YOU and your particular immune makeup.  It also takes
time, patience, and experimentation to arrive at the correct
diet, which then may change over the years.

R. Keene (Flame suit on)