Bee venom immunotherapy - how early is it effective?

Although the effectiveness of venom immunotherapy (VIT) in bee venom (BV) allergy has been well established over the past 30 years, no previous study has demonstrated its efficacy immediately after reaching the maintenance dose (MD). We examined the effectiveness of bee VIT within a week after the MD was achieved.

Bee venom allergic patients underwent conventional or rush VIT. Within 1 week after reaching the 100 microg MD, patients were challenged with a live bee sting.

Seventy-nine of 107 patients (73.8%) who reached the MD agreed to be challenged. Seventy patients (88.6%) tolerated the sting uneventfully. Four patients (5.1%) developed a very mild local transient rash and continued to receive the 100 microg MD. In five patients (6.3%), the sting resulted in a mild-moderate systemic reaction. In four of these, the MD was increased to 200-250 microg. All four patients uneventfully tolerated a repeated sting that was performed within 1 week after achieving the increased MD in three patients and after 14 months in the fourth patient.

Bee VIT is effective in most patients immediately after the conventional MD has been reached. In the minority of patients who are not protected with this dose, an increased MD will provide appropriate protection immediately after it is achieved. Thus, the dosage of the MD seems to be the major factor affecting protection from re-stings rather than the accumulated venom dose or the duration on the MD.