Prepare oatmeal for use in a bath by placing 1 cup of oats into a blender and processing until it becomes a fine powder, notes Stephanie Brown for About.com. The powder is processed enough when 1 tablespoon added to a glass of warm water gives the fluid a milky look and silky feel.
Prepare the oatmeal bath by drawing a tub of tepid water, explains Elizabeth Forester for HowStuffWorks. Tepid water is less likely to dry the skin and contribute to further itching. Add the powdered oatmeal to the tub as it is filling to ensure even mixing. Soak in the water for 10 minutes or as directed by a doctor. Rinse skin with clean, tepid water to remove any stickiness from the skin. Gently blot dry, avoiding vigorous rubbing. Repeat up to three times a day to soothe itchy skin.
Doctors are not sure why oatmeal baths work to soothe irritated skin, states Forester. However, two chemicals in oatmeal, phenols and avenanthramides, may have anti-inflammatory abilities. They also hold on to moisture, have antioxidant abilities and absorb ultraviolet light, making them an effective skin protectant, states Kurtz and Wallo for the Journal of Drugs in Dermatology.
There are no known side effects or drug interactions associated with oatmeal baths, according to WholeHealthMD. To avoid irritation, do not get oatmeal bathwater in the eyes, and stay away from an oatmeal bath if the irritated area is inflamed or infected.