The best remedy is protection. Choose from a range of repellants to protect yourself from sandfly and mosquito bites.
If you are bitten then you can use a topical cream to take away the redness and itch. You can use a mild steroid cream or a non steroid cream depending on your preference.
If you have been bitten all over then an oral antihistamine like will be effective.
Alternatively - there are natural remedies available as well which help support the body's immune system to cope with the effects of the bite/sting like Naturo Pharms Lampona Cylindrata which supports the body when bitten by the white tailed spider.
Insect Repellants - By Brand