Many studies have also evaluated the effectiveness of colloidal oatmeal in the treatment of moderate to severe xerosis, or dry skin. These studies have collectively demonstrated significantly greater improvements from baseline in skin barrier function (via corneometer measurements of transepidermal water loss), overall dryness, and itch, compared to either vehicle alone, similar ceramide cream, or prescription barrier cream.5–7 Treatment with colloidal oatmeal lotion has also been found to have rapid and lasting efficacy, with a study by Nebus et al of thirty patients between the ages of 18 and 55 demonstrating significant improvement in measurements of transepidermal water loss and xerosis after only 4 days of use. Improvements were maintained after a 48-hour regression period.8
Psoriasis is a common, chronic skin disease affecting approximately 2% of the population that is characterized by dysregulation of the innate immune system and uncontrolled keratinocyte proliferation.9 Patients often suffer from dryness and roughness, which leads to significant psychosocial distress. Colloidal oatmeal has also demonstrated benefit in patients with mild psoriasis. In a 4-week study of 60 adult females with psoriasis and self-reported sensitive skin, subjects were instructed to apply 1% colloidal oatmeal at least once per day to the whole body with a focus on dry patches. After 4 weeks of use, participants reported 45% improvement in itch and desquamation compared to baseline scores. 96% of patients reported that the 1% colloidal oatmeal lotion helped to reduce both the severity and number of appreciable patches.10
Successful treatment of mollucsum contagiosum (MC) with colloidal oatmeal has also been described. Molluscom contagiosum, a skin infection caused by a DNA poxvirus, is one of the most common viral skin infections seen in children. In an open study, 6 children aged 5–11 years with at least 10 cutaneous lesions of MC were treated with a zinc oxide cream containing colloidal oatmeal extracts (Avena rhealba). After 4 weeks of therapy, 4 of the 6 patients had complete resolution of their lesions and the 2 remaining patients had a >50% decrease in the total number of their lesions.11 Pazyar et al posit that the antiviral properties of colloidal oatmeal extract are likely due to the inhibitory effects on eicosanoid formation, expression of cytosolic phospholipase A2, and arachidonic acid mobilization in human keratinocytes.12
Aside from its demonstrated benefit in a variety of dermatoses, colloidal oatmeal has also been continuously reported as safe and effective. Twelve independent studies evaluated irritant and allergic reactions via patch testing of various skin care products containing oatmeal in various formulations including lotions, creams, serums, and cleansers. Of the 2565 participants, only 20 subjects demonstrated transient lowlevel reactions such as faint erythema, and only 3 subjects demonstrated grade 1 reactions with edema.13 Criquet et al further described two studies evaluating the ocular tolerance of a facial cleanser in 43 female subjects with normally sensitive eyes. Eye reactions were documented in only 3 subjects and confirmed by clinical opthalmologic evaluation.13 In a total of 47 patients, clinical efficacy was demonstrated over the course of six weeks via skin hydration, reduced desquamation index, and subjective evaluation of signs of skin dryness after application. Dermatologist assessment demonstrated significant improvement of skin dryness, desquamation, and skin roughness in treated areas compared to controls.13 Ultimately, the U.S. Food and Drug Administration generally recognizes colloidal oatmeal as safe and effective.
Systemic Conditions With Skin Manifestations
Colloidal oatmeal has been reported to be of benefit in the treatment of skin manifestations of systemic diseases. Diabetes mellitus is commonly responsible for skin changes including diabetic dermopathy and discrete to mild xerosis. Pierard et al describe a continuum between a sensation of dry skin, xerosis, and icthyosiform presentations of the shins and feet of diabetic patients.14 In a study of 46 patients with diabetes and moderate dryness of the lower legs, twice daily use of an oatmeal lotion with avenanthramides and oat oil resulted in significant improvements in erythema, fissuring, scaling, and tactile roughness as early as 1 week into use. Improvements continued through 4 weeks of treatment.15
Dermatologic Side Effects Associated with Cancer Therapy
Oats have also been described in the literature to be of benefit in addressing skin toxicities associated with oncologic therapies. Targeted therapies, a newer genre of cancer treatment that specifically targets tumor cells, are well known for their significant dermatologic toxicities.16 Over 50 distinct dermatologic toxicities have been reported in association with more than 30 anti-cancer agents, the most common of which include hand-foot skin reactions, nail changes, papulopustular (acne-like) eruptions, pruritus (severe itching), secondary malignancies, new neoplasms, and chemotherapy-induced alopecia (hair loss or spot baldness).17–18 Of particular interest and study are epidermal growth factor receptor (EGFR) inhibitors and tyrosine kinase inhibitors, which are used to treat a broad range of solid organ malignancies. Treatment and optimal management of these cutaneous effects is important, as they can be severe enough to cause patients to discontinue treatment.