Risk Factors in Hymenoptera Venom Allergy

. Risk factors should be part of the decision, of which patient should be offered venom immunotherapy (VIT) and how VIT should be performed. Risk factors for a severe systemic anaphylactic reaction (SAR) after a Hymenoptera field sting include a preceding less severe sting reaction, a wasp sting, an increased baseline serum tryptase concentration (BSTC), mastocytosis, older age, ACE inhibitor medication, and male gender. During VIT, treatment with honey bee venom is the most important risk factor for a SAR. Further risk factors include a high BSTC (for vespid VIT only), presence of venom specific IgE in serum, any antihypertensive medication during therapy, and an ultra-rush protocol for build-up. Treatment failure is more common in patients suffering from honey bee venom allergy, high BSTC (for vespid VIT only) or mastocytosis, and in those who had experienced side effects during VIT. Besides discontinuing antihypertensive medication or switching to a moderate type of dose increase during build-up, little can be done to minimize the risks associated with VIT. Increasing the maintenance dose may improve the efficacy of VIT. In patients with a particularly high risk for treatment failure, or in case of treatment failure, VIT should include an increased maintenance dose right from the beginning. Usually, 200 µg will be sufficient.