D2.228 - Changes in temperature during allergic reactions to food in human volunteers

Systemic anaphylaxis in animal models of food allergy is associated with significant falls in both core and body surface temperature, even in the absence of shock. This may be multifactorial: due to shock-induced reduction in thermogenesis, heat loss due to peripheral vasodilation, and/or altered hypothalamic thermoregulation. Our aim was to evaluate changes in body temperature during acute allergic reactions to peanut in human volunteers.

Post-hoc analysis of detailed data in peanut-allergic adults who underwent double-blind, placebo-controlled food challenges in the TRACE peanut study (clinicaltrials.gov NCT01429896). Body temperature was measured using infrared tympanic thermometry before challenge, prior to each challenge dose, and immediately post-challenge on both active and placebo days.

Data were analysed from 123 adults (median age 25 years, IQR 19–28 years; 55% female), of whom 24 (20%) experienced anaphylaxis (WAO criteria). Acute allergic reactions were associated with a small but significant increase in body temperature at time of reaction, with a mean rise of 0.17ºC [95%CI, 0.1–0.24ºC; p<0.001]). There was no significant change on placebo days. The temperature change in patients with anaphylaxis was not different to those with less severe reactions (mean rise in temperature of 0.18ºC versus 0.17ºC respectively, p=0.92).

These data suggest that the physiological consequences of acute allergic reactions to food in humans are very different from those seen in animal models.