Colloidal oatmeal is derived from dehulled oat kernels and the term "colloidal" simply means oats ground into a fine powder.
Use of finely ground colloidal oatmeal (Avena sativa L.) to soothe skin is an ancient practice, and the use of oatmeal baths is still common to help control pruritic, inflammatory skin manifestations like poison ivy and chicken pox.
The active components include polysaccharides, proteins, lipids, enzymes, saponins, flavonoids, vitamins, and prostaglandin synthesis inhibitors.
Colloidal oatmeal functions as a cleanser, moisturizer, buffer, as well as a soothing agent. The avenanthramide compounds in oats are also known to have protective anti-inflammatory properties.(1) Colloidal oatmeal has been used to treat atopic dermatitis and inflammatory skin diseases and is known to repair barrier dysfunction, reduce skin inflammation and irritation.(2)
The anti-pruritic effects of colloidal oatmeal were demonstrated in a study of burn wounds. Patients who applied to healing burn wounds a topical moisturiser containing colloidal oatmeal reported significantly less itch and used fewer antihistamines than patients who used the vehicle moisturiser without colloidal oatmeal.(3)
Colloidal oatmeal also provides protective and moisturizing benefits, thought to derive from the high concentration of starches and beta-glucans that hold water.(3) The botanical is high in oat phenols, some of which are strong ultraviolet absorbers and are under investigation as sunscreen ingredients.(3)
1. Kurtz ES, Wallo W. Colloidal oatmeal: history, chemistry and clinical properties. J Drugs Dermatol.2007 Feb;6(2):167-70.
2. Schiapparelli P, Allais G, Castagnoli Gabellari I, Rolando S, Terzi MG, Benedetto C. Non-pharmacologicalapproach to migraine prophylaxis: part II. Neurol Sci. 2010 Jun;31 Suppl 1:S137-9.
3. Matheson JD, Clayton J, Muller MJ. The reduction of itch during burn wound healing. J Burn Care Rehabil. 2001 Jan-Feb;22(1):76-81