Not all perioperative anaphylaxis looks the same. In a Paris cohort of 72 patients with severe, IgE-proven reactions, Dewachter and colleagues found that every fatal or near-fatal case — 6 of 27, vs 0 of 45 — began with early cutaneous vasoconstriction: pallor, piloerection, sweating, sometimes cyanosis, paired with bradycardia instead of the expected tachycardia.
That pattern signals profound hypovolemia from capillary leak, and the lessons are practical: lead with aggressive, don't reach reflexively for atropine to "fix" the bradycardia — it preceded ventricular fibrillation in these cases — and titrate epinephrine in small doses rather than reflex 1 mg boluses. Some apparent "refractory anaphylaxis" was actually catecholamine-stressed, failing myocardium.
Pale and bradycardic is not mild anaphylaxis. It may be the most dangerous kind.
Dewachter P, et al. J Allergy Clin Immunol Pract. 2026;14(10):2295-2309.e2.
https://www.jaci-inpractice.org/article/S2213-2198(26)00585-4/fulltext