New Science to Support 50 Years of Colloidal Oatmeal Use in Dermatological Practice

Lyn Guenther, MD, FRCPC

Division of Dermatology, University of Western Ontario, London, ON, Canada

Introduction

Oatmeal has been used for centuries in skin care as a soothing agent to relieve itch and irritation associated with various skin conditions, such as xerotic and inflammatory dermatoses. It contains a number of compounds with moisturizing, cleansing, buffering, anti-inflammatory, anti-pruritic and anti-oxidant properties. Products containing colloidal oatmeal are well tolerated with only rare reports of allergic contact dermatitis. Clinical studies support the adjunctive use of these products in the treatment of atopic dermatitis.

Background

• The oldest oat grains were found in Egypt about 2000 BC.¹
• The nutritional value of oatmeal and its benefits when used as a topical have been recognized since Roman times as shown in texts by Pliny, Columella and Theophrastus.^1,2
• Oats were introduced to North America at the beginning of the 17th century.¹
• Of the cultivated oats today, more than 75% belong to the Avena sativa (A. sativa) type.²
• In the 1930s, oatmeal started to be used for its cosmetic benefits in facial masks and bath oils and for cleansing, moisturizing and relieving itching.²
• In 1945, a ready to use colloidal oatmeal for skin care became available.
• The colloidal oatmeal, which was made by finely milling dehulled oats to a powder, contained a concentrated starch-protein fraction of the oat grain.^2,3
• In 2003, the US FDA approved colloidal oatmeal as a skin monograph ingredient which can temporarily protect and help relieve minor skin irritation and itching.^2,3
• Today there are many formulations of colloidal oatmeal including cleansers, washes, bath products, creams, lotions, shampoos and shaving gels.^2,3

Components of Colloidal Oatmeal and Their Therapeutic Effects

• Colloidal oatmeal contains starch (65-85%), proteins (15-20%), lipids (3-11%), fiber (5%), and beta-glucans (5%).³
• The lipid content is much higher than in other cereal grains, with unsaturated triglycerides rich in unsaturated fatty acids, being the most abundant lipids.²
• The phenolic compounds avenanthramides, ferulic and caffeic acids, glyceryl esters of hydroxycinnamic, and p-Coumaric in oat flour have antioxidant activity and protect the lipids from oxidation.^2,3
• Avenanthramides also have anti-inflammatory and anti-pruritic properties. They have been shown to decrease activation of nuclear factor-kappa B (NF-κB) and production of proinflammatory cytokines, and reduce oxazolone-induced contact hypersensitivity, histamine-mediated itch and resiniferatoxin-induced neurogenic inflammation.³
• Flavonoids in oat absorb in the 320-370nm UVA range, while saponins with their large lipophilic region and short chain of sugar residues have a soap-like action.²
• Beta-D-glucan is a hydrocolloid which binds water, forming a colloidal film holding moisture in the stratum corneum.²
• Colloidal oatmeal can also act as a skin buffer, restoring the normal pH of the skin.²
• Alpha-tocopherol, also present in oatmeal, has antiinflammatory and anti-photodamage effects and can inhibit the synthesis of prostaglandin E2.²

Safety and Colloidal Oatmeal Skin Care

• Although more than 8 million oat-based cosmetics are sold yearly, there are very few reports of allergic contact dermatitis or contact urticaria.⁴ In the few patients with cutaneous adverse events to topical oat, the reactions were generally very mild and often did not recur with repeat applications.⁵
• In a double-blind, randomized, controlled study, colloidal oatmeal was applied for 15 minutes as an open patch test, and under a patch for 24-48 hours. No urticarial or contact allergic reactions occurred.⁶
• Transient low-level reactions have been reported in 1% of 2,291 men and women treated in 12 independent repeat insult patch test studies of 12 oatmeal-containing skin care products.⁵ No reactions occurred in 2 safety-in-use studies involving 80 adults and 30 children, of which one-third had atopic dermatitis.⁵
• In 302 children who underwent atopy patch tests, a 15% positive result was reported as was a 19% positive skin prick test.⁷

Efficacy of Topical Colloidal Oatmeal

• Colloidal oatmeal skin care can alleviate dry skin. In a 2-week, single-blinded study of subjects with Fitzpatrick skin types IV-VI, a significant improvement in moisturization and skin brightness was seen within the first day (p<0.05) and was maintained throughout the study period, when using the moisturizer containing colloidal oatmeal twice daily.⁸
• Moisturizers that soothe pruritus, hydrate, protect and restore the skin barrier are an essential part of the management of atopic dermatitis (AD).^9,10 They may be first-line in mild AD or with more severe disease, or complementary to prescription medications for enhancement of treatment efficacy and for their steroid-sparing effects.^3,5,9,11
• In a 6-week randomized, controlled study involving 173 infants with moderate to severe AD, the group treated with oat moisturizer demonstrated significant improvements in the Scoring Atopic Dermatitis Index (SCORAD) and quality of life scores (p<0.0001).¹² Further, the quantity of moderate- and high-potency corticosteroids that were used decreased by 7.5% and 42% (p<0.05), respectively.¹²
• In an open-label, 12-week, multicenter study involving 99 patients aged 6 months to adulthood with mild-to-moderate AD, the efficacy and tolerability of an A. sativa extract based moisturizing cream used twice daily showed that by week 12, the SCORAD index improved by 48%.¹³ Skin hydration assessed in selected patients showed a 90% increase at week 8 and an increase of 100% at week 12. The results reported by patients indicated similar trends. The quality of life questionnaires showed significant improvement by week 4. Moreover the steroid sparing effect shown by Grimalt et al, was confirmed in this study.^12,13
• A study conducted in Brazil, that evaluated colloidal oatmeal cream in an open trial in 75 AD patients aged 3-50 years showed significant improvements in SCORAD from baseline as early as week 4.¹⁴ At the end of the study, the SCORAD improvement was very similar to data reported by Nollent (2012).¹⁴
• Patients on chemotherapy with epidermal growth factor receptor inhibitors and tyrosine kinase inhibitors more often than not develop cutaneous adverse effects including acneiform eruptions which can preclude continuation of the treatment. In a study of 10 evaluable patients, treatment with an oatmeal-based lotion resulted in a complete clearing of the cutaneous adverse effects in 6 patients and a partial response in the remainder. ³

Conclusion

There are many different formulations of colloidal oatmeal including cleansers, washes, bath products, creams, lotions, shampoos and shaving gels. Colloidal oatmeal contains a number of components which contribute to its moisturizing, cleansing, buffering, anti-inflammatory, anti-pruritic and antioxidant properties.

Products containing colloidal oatmeal are well tolerated with only rare reports of allergic contact dermatitis. Studies have shown that A. sativa based products significantly decrease skin dryness, itch and irritation, improving quality of life in patients with mild to severe AD. Colloidal oatmeal use in patients with AD has been shown to significantly reduce topical corticosteroid consumption.

References

1. Gibson L, et al. Origin, history, and uses of oat (Avena sativa) and wheat (Triticum aestivum).
2. Kurtz ES, et al. J Drugs Dermatol. 2007;6(2):167-70.
3. Cerio R, et al. J Drugs Dermatol. 2010;9(9):1116-20.
4. Goujon-Henry, C et al. Allergy. 2008;63:781-2.
5. Criquet M, et al. Clin Cosmetic Invest Dermatol. 2012;5:183-93.
6. Pigatto et al: Am J Contact Dermatitis. 1997;8:207.
7. Boussault P, et al. Allergy. 2007;62(11):1251-6.
8. Nebus J, et al. J Am Acad Dermatol. 2004;50:P77.
9. Lebwohl M, et al. Cutis. 2005;76(suppl 6):7-12.
10. Eichenfield LF, et al. J Am Acad Dermatol. 2003;49(6):1088-95.
11. Fowler JF, et al. J Drugs Dermatol. 2012;11(7):804-7.
12. Grimalt R, et al. Dermatology. 2007;214(1):61-7.
13. Nollent V, et al. Multi-centric clinical study on infants, children and adults with atopic dermatitis. Poster EADV Congress, 27-30 September 2012, Prague, Czech Republic.
14. Nebus J, et al. The Dermatologist. 2012;20(10)(suppl):1-4.