Background Allergic reactions to lettuce (Lactuca sativa) are not too
frequent and few cases of systemic adverse reactions after its ingesti
on have been described. Objective We report a case of clinical sensiti
zation to lettuce on a patient who presented mucocutaneous manifestati
ons after its ingestion, with positive skin tests, histamine release t
est and serum specific-IgE to lettuce. The allergens responsible for t
his sensitization were also characterized by means of SDS-PAGE immunob
lotting. Materials and methods We performed skin tests, histamine rele
ase test, serum specific IEE determination and CAP inhibition with let
tuce and mugwort (Artemisia vulgaris) extracts. An aqueous and enriche
d lettuce (from loose leaf type) extract was subjected to SDS-PAGE imm
unoblotting for determination of its IgE-binding components. Results a
nd Conclusions CAP inhibition showed antigenic community between lettu
ce and mugwort. Four protein bands from the lettuce extracts with mole
cular weights of 50, 43, 39 and 16 kDa exhibited IgE-binding propertie
s.