I quote from the treatment page:
"The majority of insect bites cause itching and swelling which usually clears up within 1-2 days. Small, local reactions (reactions confined to the area of the bite) can be treated using a cold compress (such as placing a damp flannel over the affected area), and oral painkillers, such as paracetamol, or ibuprofen.
Anaesthetic, or steroid cream, such as crotamiton cream, can be used to soothe the pain of a bite. Antihistamine tablets can also help.
Do not apply cream, or ointment, to broken skin and always follow the instructions on the packet. Although the bite may be itchy, avoid scratching it because you may damage the skin, and allow bacteria to get in, leading to infection."