A nonprescription oral antihistamine, such as loratadine (Alavert, Claritin, others), cetirizine (Zyrtec Allergy, others) or diphenhydramine (Benadryl Allergy, others), may help relieve itching.
Consider whether you might prefer a type that doesn't cause drowsiness. Ask your pharmacist about options. Applying a cold compress can also help.
It's important to consult with a doctor or pharmacist if your allergy rash is severe or persistent, as they can recommend the best treatment for your specific condition.