Objective improvement in the diagnosis of immuno-allergology can only be obtained by application of reliable and reproducible immuno-biological methods, but until now, only measurements of total and specific IgE can be used and this has certain limitations. Presence of specific serum IgE, correlated with skin tests, favours a sensitization and implies nothing about the responsibility of the allergens. This is why we must consider if a definite improvement of diagnostic methods can be obtained by measurement of mediators. From an observation of food allergy to pork meat, we now show that it is possible to use sequential measurements of the mediators plasma histamine and urinary methylhistamine, ECP and serum tryptase to refine the diagnosis and provide proof of the responsibility of the food allergen. We report here a didactic observation which is characterised by reproducibility and specificity of the measurements. It illustrates the progress in diagnostic methods in allergy: we give a statistical diagnosis by measurement of antibodies and a dynamic diagnosis by measurement of mediators.