- anaphylaxis/ anaphylactic ‘shock’: life-threatening allergic reaction
=> often young people & females
=> 50-200 episodes per 100,000 person-years
=> lifetime prevalence of 0.05-2% (% of individuals at some pt in their life)
=> up to 1500 deaths per year in the USA
=> rates are increasing: 3-fold increase 1994-2004 in adults & 5-fold increase in children
What is anaphylaxis?
- 4 signs of acute inflammation (by Celsus): - rubor (redness): vasodilation
- calor (heat): vasodilation
from post-capillary venules
- tumor (swelling): plasma exudation into tissues
- dolor (pain): activated sensory nerves
- 5th sign (by Galen): loss/ disturbance of function
- anaphylaxis features:
=> rapid onset (~10-30min)
=> swelling (urticaria/ angio-oedema)
=> itching & tingling (picotements) of the skin (pruritus)
=> reddening (erythema): red rashes (éruption cutanée)
=> rhinitis (runny nose), conjunctivitis (runny eyes)
=> nausea, abdominal pain...
=> breathing difficulty (laryngeal oedema, airway constriction)
=> hypotension => fainting, dizziness...
=> tachycardia
- treatment: injections of adrenaline (epinephrine) => Epipen
Inducers of anaphylaxis
- antigen/ allergen: ‘innocuous’ protein/ chemical that triggers anaphylaxis reaction
=> food (especially children): nuts, milk, eggs, soya, blue cheese...
=> venom: bees/ wasps stings
=> drugs (especially old people): muscle relaxants (anaesthetics), antibiotics (penicillin), non-
steroidal antiinflammatory drugs (NSAIDs), aspirin
(also latex, hair dye...)