If you use a soap that you're allergic to by accident, here's what you should do. Please stop using the product as soon as you see your skin is reacting negatively to it. If necessary, an antibiotic ointment can be used to calm your skin. To begin with, the easiest method to avoid an allergic reaction to soap is to choose the proper kind. For persons with sensitive skin, hypoallergenic soap has made a huge difference. If you give this a try, you'll notice a difference immediately.