Suggest Remedy For Itchy Rashes Post An Insect Bite

I had an insect bite on the neck and developed a red rash which started spreading, then was asked to use Betamil cream which I did and took Allegra 180 tablets daily. The rash stopped but now have started getting red rashes near inner thigh. They are subsiding with betamil but once I stop applying they are erupting with itching. Please advise.