What is anaphylatic shock

Anaphylaxis = severe allergic reaction Hypersensitive response from the immune system to usually harmless substances Known as allergens e.g. peanuts etc. Results in release of histamine from mast cells Histamine is a potent vasodilator Fall in TPR and fall in mean arterial BP Histamine also causes bronchospasm and laryngeal oedema = difficulty breathing This could also be a cause of distributive shock