Anaphylactic shock in a patient with mastocytosis.

Paramedics found the woman to be in a state of pulseless electrical activity 20 minutes after the cardiovascular collapse. They immediately commenced an adrenaline infusion and performed cardiopulmonary resuscitation and intubation before transporting her to the emergency department. The adrenaline infusion was ceased after 3 hours, when she was deemed to be haemodynamically stable. On presentation, there was no apparent urticaria or angio-oedema and no sign of a bite mark. Further examination showed no signs of wheeze, cardiac failure, pulmonary hypertension or deep vein thrombosis. An electrocardiogram showed mild ST depression in leads V1–V3. Troponin levels were mildly elevated (0.63 g/L initially and 0.35 g/L 6 hours later; reference interval [RI], < 0.1 g/L), and aspirin 100 mg daily was commenced. A full blood cell count, urea and electrolyte levels and liver function tests were unremarkable. Venous blood gas analysis demonstrated a mixed respiratory and metabolic acidosis. A coagulopathy was noted, with an increased international normalised ratio (1.9; RI, < 1.5) and activated partial thromboplastin time (> 250 s; RI, 22–32 s). Toxicology and venom screens gave negative results. A chest x-ray and a computed tomography scan of the brain were normal.