First of all, stop scratching them. That will only irritate them further. You could also try taking an oatmeal bath to help soothe them.
I've found the best remedy to get rid of a rash is first Caladryl (the pink stuff we used on chicken pox) and then Cortizone 10 plus. Good luck.
Hello,
If it is sudden rashes and itchiness then it can be due to allergies or hives. You can take some OTC oral antihistamine medications like Benadryl or Claritin and see if it helps.
For mild-moderate symptoms a weak steroid may be used, whilst more severe cases require a higher-potency steroid. But they are available under prescription and should be taken only after consulting a dermatologist. Symptoms can be exacerbated by dryness of the skin. Use good quality moisturizers to prevent moisture loss from the skin.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.