Quote from Healthline: "If your skin is sensitive to products that contain Cocamidopropyl Betaine, you may notice tightness, redness, or itchiness after you use the product. This kind of reaction is known as contact dermatitis. If the dermatitis is severe, you may have blisters or sores where the product came into contact with your skin.

Most of the time, an allergic skin reaction like this will heal on its own, or when you stop using the irritating product or use an over-the-counter hydrocortisone cream.

If the rash doesn’t get better in a few days, or if it is located near your eyes or mouth, see a doctor."