What do you do if you have to treat an insect bite or a sting? Probably wash it off with water hoping it will reduce the itching and wait for the swelling to go down on its own! But here's something you can do the next time you have an insect bite. Use some aspirin. You may like to know this truth about aspirin. How it works -- Aspirin contains a pain relieving ingredient called acetylsalicylic acid which is also an anti-inflammatory agent [1]. Aspirin effectively alleviates joint pain and inflammation and works similarly on inflamed skin. How to use