sudden onset The term sudden onsets refers to an event that occurred unexpectedly and without warning leading to a marked change in a subjects previously stable condition Anaphylaxis: Case definition and guidelines for data collection, analysis, and presentation of immunization safety data. Vaccine 25 (2007) 5675–5684 SuddOnset rapid progression Brighton diagnosis result generalized urticaria or generalized erythema finding angioedema finding capillary refill time > 3s finding cyanosis finding diarrhoea finding abdominal pain finding gastrointestinal sign dry cough finding chest tightness finding erythema finding pruritus finding decreased level of consciousness finding difficulty breathing finding clinical finding