I have a red, blotchy itchy rash on my legs and feet. A cool bath helped but not fir long, I've also tried a antihistamine and a cream for bites?

Unsure of diagnosis. These lesions need to be visualized & a history needs to be obtained in order to make an accurate diagnosis. Sometimes lab testing or biopsy is necessary.
Chigger bites? Chigger bites the rash could be due to insect allergy or chigger bites, an infestation caused by mite larvae that feed on the skin. Rashes and itching caused by chigger bites looks and feels like allergies and are caused by a combination of digestive enzymes secreted by a mite and the immune response of the host causing an intense pruritus (jones, j.G. (1987). Treatment is primarily symptomatic.