Diagnosis and monitoring of Hymenoptera venom allergy : clinical aspects and new tools

Diagnosis of Hymenoptera venom allergy is commonly based on history, skin tests and in vitro IgE tests, which however are unable to predict the outcome of a subsequent sting from the culprit insect. The in hospital sting challenge is currently the only reliable procedure to assess the reactivity or tolerance to venom in patients with positive history and diagnostic tests and thus selecting those who need venom immunotherapy. The challenge as a diagnostic tool must be performed in specialized Centers because of the risk of life-threatening events in subjects with further reactions. This risk is negligible in patients treated with venom immunotherapy, therefore the sting challenge can be safely used as a tool to which the immunological monitoring, including the changes in venom specific IgE and IgG antibodies, the release of mediators and especially the switch from a TH2 to a TH1-type cytokine pattern has to be referred.