My friend has a itchy red rash on her lower stomach what could it be?

Contact Dermatitis: Belt buckle rash is a condition where the skin reacts to the metals in a belt buckle, usually nickel but other metals may be indicated too. It’s a form of contact dermatitis, signifying allergies to certain forms of metal. People with belt buckle rash or belt buckle allergy often get a raised rash where the belt buckle on belts remains in contact with the skin, such as below the belly button.