What are ways of soothing a dry, itchy rash?

It depends: It depends on the cause of the rash. If it's from irritation, for instance, washing your hands a lot, Hydrocortisone ointment (over-the-counter) will help. You can also try putting on calamine lotion, and taking Benadryl (diphenhydramine) by mouth for itching.

Have it looked at: There are many types and causes of skin rashes. Several types of inflammatory conditions of the skin, allergic reactions, and sometimes bacterial, viral or fungal infections can cause rashes on the skin. Insect bites can also be the cause of a rash on the skin. Have it evaluated by a professional and get the appropriate treatment.