What causes dryness on the plantar surface of the skin?

From the Guidelines

Dryness on the plantar surface of the skin is primarily caused by a lack of moisture and natural oils, excessive friction, and environmental factors, and can be prevented and treated by using emollients to moisturize dry skin, as recommended by the International Working Group on the Diabetic Foot (IWGDF) in their 2023 update 1. The skin on the feet naturally contains fewer oil glands than other body areas, making it prone to dryness. Common causes include:

• Wearing closed shoes for long periods
• Excessive walking or standing
• Hot showers with harsh soaps
• Low humidity environments
• Aging
• Certain medical conditions like diabetes, eczema, psoriasis, hypothyroidism, and athlete's foot To treat plantar dryness, the following measures can be taken:
• Use a urea-based foot cream (10-20% concentration) or products containing lactic acid, glycolic acid, or salicylic acid daily after bathing
• Soak feet in warm water for 10-15 minutes before gently exfoliating with a pumice stone
• Apply moisturizer and wear cotton socks overnight for better absorption
• Avoid hot showers, use mild soaps, stay hydrated, and wear breathable footwear As recommended by the IWGDF, people with diabetes who are at risk of foot ulceration should be educated to wash their feet daily, use emollients to moisturize dry skin, and cut toenails straight across 1. Additionally, the IWGDF recommends that people with diabetes who are at risk of foot ulceration should be screened annually for signs or symptoms of peripheral neuropathy and peripheral artery disease, and that those with a history of foot ulceration or lower-extremity amputation should be screened more frequently 1.

It is also important to note that the IWGDF recommends providing structured education to people with diabetes who are at risk of foot ulceration about appropriate foot self-care for preventing a foot ulcer, and that this education should include information on how to protect the feet, how to examine the feet daily, and how to rapidly contact a healthcare professional if a (pre-)ulcerative lesion is suspected 1.

In terms of prevention, the IWGDF recommends that people with diabetes who are at risk of foot ulceration should be encouraged to wear properly fitting footwear, and that those with a foot deformity or pre-ulcerative lesion should be considered for prescription of therapeutic shoes, custom-made insoles, or toe orthosis 1.

Overall, the prevention and treatment of dryness on the plantar surface of the skin require a comprehensive approach that includes education, self-care, and regular screening for signs of foot ulceration, as recommended by the IWGDF in their 2023 update 1.

From the FDA Drug Label

Indications and Usage For debridement and promotion of normal healing of hyperkeratotic surface lesions, particularly where healing is retarded by local infection, necrotic tissue, fibrinous or purulent debris or eschar. Urea is useful for the treatment of hyperkeratotic conditions such as dry, rough skin, dermatitis, psoriasis, xerosis, ichthyosis, eczema, keratosis pilaris, keratosis palmaris, keratoderma, corns and calluses, as well as damaged, ingrown and devitalized nails. The causes of dryness on the plantar surface of the skin are not explicitly stated in the drug label, but hyperkeratotic conditions and xerosis are mentioned as conditions that can cause dry, rough skin.

• Hyperkeratotic conditions can lead to dryness and roughness of the skin.
• Xerosis is a condition characterized by dry skin. 2

From the Research

Causes of Dryness on the Plantar Surface of the Skin

• Dryness on the plantar surface of the skin can be caused by various factors, including environmental conditions and lifestyle factors 3.
• The plantar surface of the skin is prone to dryness due to its unique properties, such as tangential stiffness, normal compliance, and thickness, which can vary across different locations and individuals 4.
• Exogenous factors, such as climate and environment, can contribute to dryness on the plantar surface of the skin, while endogenous factors, such as medication and hormone fluctuations, can also play a role 3.
• The use of certain medications, such as topical corticosteroids, can also lead to dryness on the plantar surface of the skin, particularly with prolonged use or application to sensitive areas 5.

Treatment and Management

• Emollients, such as urea, can be effective in treating dry skin on the plantar surface by restoring damaged intercorneocyte lipid structures and increasing the water content of the skin 3, 6.
• Urea has been shown to be a safe and effective treatment for various dermatological conditions, including xerosis, with minimal side effects 6, 7.
• The choice of treatment and management strategy will depend on the underlying cause of the dryness and the individual's specific needs and circumstances.

Factors Contributing to Dryness

• Skin thickening and skin thinning can both contribute to dryness on the plantar surface of the skin 3.
• The predominance of hydrophobic substances in intercellular constituents can regulate the humidity of the skin and contribute to dryness 3.
• Lifestyle factors, such as activity level and footwear, can also contribute to dryness on the plantar surface of the skin 4.