Risk factors in bee and Vespula venom allergy: state of the art

Background Correct recognition of risk factors enables individualized management and treatment of venom allergic patients. Methods Systematic research and review of current literature regarding the risk of (1) severe sting-induced anaphylaxis, (2) anaphylactic adverse event during venom immunotherapy (VIT), and (3) treatment failure. Results and discussion (1) Mastocytosis is the most important risk factor for severe sting-induced anaphylaxis. Hereditary α‑tryptasemia was recently identified as a genetic predictor of severe reactions. Older age is clearly associated with an increased risk; the respective impact of defined cardiovascular comorbidities has yet to be determined. Recent data do not support an aggravation of venom-induced anaphylaxis by intake of β‑blockers or angiotensin-converting enzyme (ACE) inhibitors. A higher risk in men can be attributed to more intensive exposure to stinging insects. (2) Anaphylactic side effects of VIT are most common during the buildup phase, particularly in the course of (ultra-)rush protocols involving a high number of injections and high cumulative daily doses. They are significantly more frequent during honeybee compared to Vespula VIT. Data supporting a negative effect of mastocytosis on the tolerability of VIT are scarce. Older age and cardiovascular medication are not associated with a higher incidence of VIT-induced anaphylaxis. (3) Relapsing anaphylactic reactions to both field and challenge stings are significantly more common during and after honeybee compared to Vespula VIT. Reports of severe field-sting reactions in mastocytosis patients suggest an increased risk of treatment failure which may be overcome by higher maintenance doses and longer duration of VIT