Castor oil to alleviate eczema?

Theeczema, or atopic dermatitis, is a chronic inflammatory skin disease that primarily affects children and infants, but can also manifest during adolescence or in adulthood. It results from a specific interaction between genetics and environment, and appears upon exposure to allergens such as dust mites, animal hair or pollens.

Red patches can then appear on the face, back, neck, hands, feet and flexion folds. According to several studies, 50 to 70% of children affected by eczema have a first-degree relative who has also been affected. Those suffering from it secrete large amounts of immunoglobulin E, antibodies, in response to environmental antigens.

This atopy is caused by a dysfunction of the skin barrier, due to a lack of sebum, lipids, and cell adhesion molecules production, which can no longer fulfil its protective role. Environmental allergens then penetrate the epidermis more easily and cause an inappropriate inflammatory response.

Thecastor oil (INCI: Ricinus Communis Seed Oil) is a rich and viscous oil extracted by cold pressing the seeds of the common castor plant. It possesses numerous benefits, whether for the skin or the hair, and is also used to combat certain skin diseases such as eczema. However, it is important to keep in mind that no scientific study has so far highlighted the effects of castor oil on people suffering from eczema.

The properties of castor oil, which are discussed in the following paragraph, are indeed interesting for people suffering from eczema. However, it should be kept in mind that these have been demonstrated on individuals without any skin problems. Moreover, castor oil is only a complementary solution in the fight against eczema and should not replace treatments prescribed by a dermatologist.

• Castor oil soothes redness and itching.

  The ricinoleic acid found in castor oil has a anti-inflammatory activity. Indeed, this fatty acid can inhibit the production of certain prostaglandins, inflammatory molecules involved in sensations of pain. Furthermore, ricinoleic acid is capable of blocking the synthesis of pro-inflammatory cytokines such as interleukin-1 (IL-1) and tumour necrosis factor (TNF-α), molecules that play a role in triggering and maintaining inflammation. These various actions of ricinoleic acid help to limit redness and itching characteristic of atopic dermatitis.

• Castor oil reduces oxidative stress.

  Castor oil contains vitamin E, which has antioxidant properties. This allows castor oil to protect the skin from damage caused by free radicals. These are responsible for peroxidative damage to cell membranes and can disrupt the skin's hydrolipidic film, which is already lacking in skin affected by eczema. Furthermore, oxidative stress can lead to an increase in the production of pro-inflammatory cytokines, which are involved in the pathogenesis of this disease. Castor oil, by donating an electron, neutralises and stabilises these reactive species, which can help to reduce skin inflammation.

• Castor oil inhibits microbial proliferation.

  Studies have shown that, in some cases, eczema is linked to an infection by dermatophytes, fungi that feed on keratin. However, the undecylenic acid contained in castor oil has a antifungal activity against certain dermatophyte pathogens. The application of this vegetable oil thus helps to limit the multiplication of fungi that contribute to intensifying eczema.

• Castor oil potentially has healing properties.

  The healing process is crucial in managing atopic dermatitis. Indeed, damaged skin allows bacteria and allergens to penetrate more easily, thereby causing more inflammatory reactions. However, there are reasons to believe that castor oil has a healing effect. Indeed, a study showed that its daily application on a horse's wound significantly accelerated the healing process. This study was conducted on a horse and not on humans, so it is appropriate to exercise caution. Nevertheless, we can hypothesize a similar mechanism in human skin and a healing property of castor oil.

• MANZINI S. & al. Effect of ricinoleic acid in acute and subchronic experimental models of inflammation. Mediators of Inflammation (2000).

• IQBAL J. & al. Antioxidant, antimicrobial, and free radical scavenging potential of aerial parts of Periploca aphylla and Ricinus communis. ISRN Pharmacology (2012).