At what venom concentration are false-positive results to intradermal testing more likely?

When conducting intradermal testing for venom allergy, false-positive results are more likely to occur at venom concentrations greater than 1 μg/mL. This is primarily due to the heightened sensitivity of the skin's immune response at these higher concentrations. At elevated levels of venom exposure, there is an increased probability of non-specific reactions or irritative responses that do not necessarily indicate a true allergic reaction.

Higher concentrations can activate mast cells and basophils more readily, leading to a release of mediators that provoke reactions similar to those of a true allergy, in this context, reflecting exaggerated dermal reactivity. This responsiveness can give rise to incorrect interpretations where a positive result is noted, although the patient may not actually have an allergy to the venom being tested.

In contrast, lower concentrations, such as those below 1 μg/mL, typically produce fewer nonspecific positive reactions, making them more reliable for determining true allergic sensitization. Therefore, the risk of false positives significantly mitigates when venom concentrations are maintained below this level, emphasizing the importance of selecting the appropriate concentration range to improve test specificity.