Summarize the following:
Washing your mosquito bite will clean the surrounding skin and reduce the chance of an infection. Both of these treatments can reduce itching. Calamine lotion is an antipruritic with zinc oxide and ferric oxide that is used to treat itching. Over-the-counter hydrocortisone has a small amount of steroid that helps relieve itching and is also widely used. Icing the mosquito bite will help reduce pain and swelling. Hold the ice pack on your bite for 10 minutes at a time.

Summary:
Wash the bite with soap and cold water as soon as possible. Apply calamine lotion or a Hydrocortisone (anti-itch) cream to the bite. Hold an ice pack over the bite.