Why Do Mosquito Bites Itch?

💡 The Answer

• When a female mosquito feeds, she injects saliva containing anticoagulants into your skin to prevent blood from clotting.
• Your immune system identifies these foreign proteins and triggers mast cells to release a chemical called histamine.
• Histamine causes local blood vessels to expand, which results in the characteristic swelling, redness, and inflammation.
• This inflammatory response irritates nearby nerves, which then send the persistent itching signals to your brain.