Despite the wide use of pine nuts, the fruit of Pinus pines. only a few rep
orts of allergic reactions to them have been published. We present herein a
case of food allergy to pine nuts in a patient who showed no clinical symp
toms to pine pollen despite the presence in her serum of specific IgE antib
odies. In order to verify whether the reaction against pine nuts was IgE me
diated, specific IgE against pine nuts and pollen were evaluated by skin-pr
ick test, prick by prick and RAST: Immunoblotting and immunoblotting-inhibi
tion were used to evaluate the allergenic components of both extracts and t
heir cross-reactivity. Prick by prick with fresh pine nuts and PAST with pi
ne not and pine pollen extracts showed that the patient had high levels of
specific IgE against both extracts. Immunoblotting experiments showed the p
resence in serum of IgE antibodies against several components in pine nuts
and pollen. Immunoblotting-inhibition experiments demonstrated the presence
of some cross-reacting components. These data confirm the existence of foo
d allergy induced by pine nuts. This sensitization to pine nuts developed w
ith no symptoms of pine pollinosis. Development of pollinosis may require a
longer time of exposure to allergens. Based on the cross-reactivity betwee
n pine nut and pine pollen extracts, cosensitization to these two allergens
could be possible.