Background Insect Stings with the venoms of Hymenoptera species are well recognized as leading directly to allergic reactions in sensitised individuals. As with other hymenoptera venoms – Venom specific allergen Immunotherapy (VIT) to Jack Jumper Ants (JJA) Myrmecia pilosula has demonstrated efficacy in preventing the direct morbidity associated with severe venom-associated allergic reactions. Despite this, the indirect morbidity of severe allergy on associated background health related quality of life (HR-QoL) has not previously been assessed in patients with JJA venom allergy. Materials and methods M pilosula venom-allergic patients referred for treatment in a specialized quaternary venom treatment centre were surveyed with a venom specific HR-QoL questionnaire before and after receiving 12 months of allergen-specific venom-immunotherapy (VIT) according to JJA. A smaller subgroup also repeated this questionnaire after receiving JJA sting-challenge. Results 53 patients completed both pre-VIT and post-VIT QoL questionnaires. 83% of these patients achieved a minimal important difference (MID) of increased change in QoL of >0.5. Mean HR-QoL improved by 1.85, NNT = 1.2. There was no statistically significant difference when stratified by index-reaction grade, but appeared to be greater impairment, and subsequent improvement, Female vs Male. In the subgroup of 22 patients surveyed after VIT & re-surveyed after supervised sting challenge, Mean HR-QoL improvement 0.7, and 50% achieved a MID >0.5; therefore giving a ‘Number needed to sting’ = 2.0. Patients with the largest impairment in HR-QoL appeared to benefit the most from sting-challenge. Conclusion In JJA venom allergy the magnitude of indirect allergic morbidity, measured by HR-QoL, appears to be a separate phenomenon to that of the direct morbidity of clinical allergic sensitivity [as measured by index reaction grade.] Patient factors including gender may be important considerations for this indirect morbidity. As with direct allergic sensitivity, improvements in indirect morbidity can also be obtained by VIT treatment. In addition, formal supervised exposure with sting-challenge in patients may provide additional improvements in those with significant persistent allergy-related QoL impairment.
