Following the bite in August, 2001, the reaction developed rapidly, and he immediately lost consciousness and went into cardiac arrest before the ambulance arrived. Because of delayed resuscitation, he had hypoxic brain damage to the basal ganglia, resulting in spastic tetraplegia. Despite having only slightly raised serum tryptase of 11·5 ?g/L (normal range <11·4 ?g/L), bone marrow examination showed spindle shaped mast cells expressing CD25, and the typical Kit-mutation (D816V) was detected by PCR of peripheral blood leucocytes.1 From the patient's description of the appearance of the mosquitoes that bit him, and knowledge of the geographic region where the incidents occurred, Culex pipiens was identified by an expert from the Bernhard Nocht Institute, Hamburg, Germany, as the most likely of the 100 known mosquito species in central Europe to be responsible for inducing such reactions.