Household ammonia is a popular and effective anti-itch remedy. It is the active ingredient in many over-the-counter mosquito bite remedies. The ammonia changes the skin's acidity (pH), countering some of the chemical reactions that make you itch.
What To Do
Dampen a cotton ball with ammonia and wet the area affected by the bite.
This treatment works best on fresh bites. Only use household ammonia, which is diluted, not ammonia from a science lab, which is too concentrated. If you have sensitive skin, you'll probably want to skip this treatment and opt for one that is gentle for your skin.
Also, Meat tenderizer contains enzymes, such as papain, that tenderize meat by breaking the chemical bonds that hold the muscle fibers together. Meat tenderizer is effective against insect stings and other types of venom because it breaks the proteins that cause a reaction. Although it's unlikely meat tenderizer can do much good once a bite has had a chance to swell up, if you apply it immediately after you are bitten or shortly afterward, it may deactivate the chemicals in the mosquito saliva that will make you itchy and red.
What To Do
Either apply meat tenderizing powder directly to the bite area or mix it with a small amount of water. Leave it on for a couple of minutes, but not too long or you're likely to tenderize yourself! This is a safe remedy, but since many products contain herbs and spices, it might cause itchiness of its own if you have sensitive skin.