[The determination of specific IgE in allergy diagnosis. The clinical significance of specific IgE in drug allergies]. [Article in Italian]

IgE-mediated allergic reactions to drugs may be diagnosed on the basis of anamnestic criteria, clinico-pathological manifestations as well as by the measurement of allergen-specific IgE. The concordance of these diagnostic procedures was investigated in 50 patients with a history of sensitivity to penicillin (12), sulphamethoxazole (9) or both (14), aspirin (2) and pyrazolones (13). All subjects displayed chronic urticaria/angioedema syndrome. Optimal concordance values were observed for penicillin and sulphamethoxazole, while no specific IgE were detected in the ASA-sensitive group. False positive results were noted in pyrazolone-sensitive patients with high total IgE levels. Based on these results, serological methods that detect drug-specific IgE may be carefully used as complementary diagnostic procedure only in those patients in whom an adverse reaction to antibiotics is suspected.