2.How does anaphylaxis impact the body and how did the epinephrine help counteract that?

Question

Case Study

A 60-year-old woman was fit and well until late in the summer she was out tending to her lovely tulip garden when she was stung on the back of her right hand by a pesky wasp. This was nothing new, unfortunately as she had been stung a couple times in the last two weeks. With in minutes after this sting Charlotte fell to the ground and looked as though she was becoming pale/grayish and was gasping for air. After five minutes it was getting worse, but likely a neighbor doctor rushed over and administered an epinephrine shot, which provided support until the ambulance could arrive.

Answer 1

Hi Raven!

Anaphylaxis happens when your body has an overwhelming allergic reaction – in this case, likely due to either the wasp sting or the tulips. As a part of this overwhelming response, your lungs start to get very tight (causing the gasping for air seen here) and blood pressure gets very low (causing the pale/grayish appearance) ultimately due to histamine release from mast cells. Histamine causes widespread vasodilation which decreases blood pressure.

Epinephrine counteracts all of these problems caused by anaphylaxis! It acts on alpha-1 receptors in blood vessels to cause vasoconstriction, bringing up blood pressure back to normal levels. It also acts on beta-2 receptors to cause bronchodilation, opening up the airway and allowing for breathing to return to normal. For this reason, intramuscular epinephrine is widely agreed upon as the first-line treatment for anaphylaxis. Hopefully that helps! Feel free to reach out if you have more anatomy/pathophysiology questions, I love this stuff.

Warmly,

Josiah