Cracked heels, also known as heel fissures, are a common issue faced by many, especially those with dry skin conditions. They occur when the skin around the heels becomes dry and thick, eventually leading to painful cracks. While anyone can experience cracked heels, individuals with underlying conditions like diabetes are particularly prone to more severe cases due to compromised skin integrity and loss of sensation. Two commonly recommended topical agents for treating cracked heels are urea and lactic acid, both of which play a key role in skin hydration and exfoliation. This article explores the benefits and drawbacks of using these agents, their impact on diabetic patients, and the recommended strengths for effectively treating cracked heels.

Causes and Symptoms of Cracked Heels

Cracked heels are often the result of dry skin (xerosis) and pressure on the feet, particularly the heels. Factors such as prolonged standing, obesity, wearing open-back shoes, and walking barefoot can exacerbate the condition. For individuals with diabetes, peripheral neuropathy and poor blood circulation can lead to a reduced ability to sweat and produce natural oils, increasing the likelihood of developing dry, cracked skin.

Symptoms of cracked heels include:

• Dry, flaky skin around the heel
• Thickened skin (calluses)
• Pain, especially when walking or standing
• Bleeding or infection in severe cases

Urea: Benefits, Drawbacks, and Clinical Evidence

Urea is a naturally occurring substance in the skin, where it plays an important role in maintaining moisture levels. In topical formulations, urea is often used in concentrations ranging from 10% to 40% to treat various skin conditions, including cracked heels.

Benefits of Urea:

1. Hydration: Urea is a humectant, meaning it draws moisture into the skin, helping to alleviate dryness and soften thickened skin.
2. Exfoliation: At higher concentrations (20% and above), urea also has keratolytic properties, meaning it helps break down dead skin cells, which is crucial for treating the thickened, callused skin around cracked heels.
3. Enhanced Penetration: Urea can increase the absorption of other topical agents, making it effective in combination treatments.
4. Safe for Diabetic Patients: In appropriate strengths, urea-based creams can be used safely by diabetic patients, as they hydrate and soften the skin without compromising its integrity.

Drawbacks of Urea:

1. Irritation: High concentrations of urea (especially above 30%) can cause skin irritation, burning, or stinging, particularly in sensitive or broken skin.
2. Overuse Concerns: For diabetic patients, excessive exfoliation from higher concentrations could potentially cause more harm than good, especially if cracks are deep or bleeding. It's important to use the appropriate strength to avoid complications and have someone regularly inspect their feet.

Clinical Evidence:

Clinical studies have demonstrated the efficacy of urea in treating xerosis and cracked heels. A randomized controlled trial published in the Journal of Dermatological Treatment found that a 25% urea cream significantly improved skin hydration and reduced heel fissures compared to a placebo over four weeks. For diabetic patients, a study in the Journal of Foot and Ankle Research highlighted that urea-based creams were effective at improving skin barrier function without increasing the risk of skin injury or infection.

Lactic Acid: Benefits, Drawbacks, and Clinical Evidence

Lactic acid, an alpha-hydroxy acid (AHA), is another popular ingredient used for treating dry, cracked skin. It works by gently exfoliating the outer layer of dead skin cells and improving the skin's natural moisture balance.

Benefits of Lactic Acid:

1. Exfoliation: Lactic acid promotes cell turnover and removes dead skin cells, helping to smooth out rough patches and reduce callus formation.
2. Hydration: Lactic acid also acts as a humectant, drawing moisture to the skin and improving overall hydration.
3. Mild Action: Compared to stronger exfoliants, lactic acid tends to be gentler on the skin, making it suitable for individuals with more sensitive skin, including those with diabetes.

Drawbacks of Lactic Acid:

1. Potential for Irritation: While lactic acid is generally milder than urea, it can still cause skin irritation, redness, or stinging, especially if the skin is broken or overly dry.
2. Less Potent for Severe Cases: For severe cracked heels or thick calluses, lactic acid may not be as effective as higher-concentration urea in removing tough dead skin.
3. Sun Sensitivity: As an exfoliant, lactic acid can increase the skin's sensitivity to sunlight, potentially leading to sunburn. This may be less of a concern for feet but is worth noting for patients using it elsewhere on the body.

Clinical Evidence:

Research on lactic acid's efficacy in treating cracked heels is somewhat more limited compared to urea. However, a study published in the British Journal of Dermatology showed that a 12% lactic acid cream significantly improved skin hydration and reduced scaling in patients with dry skin disorders, including xerosis. Its ability to gently exfoliate while enhancing moisture makes it a viable option, particularly for mild to moderate cases of cracked heels.

Urea vs. Lactic Acid: Which Is Better for Cracked Heels?

The choice between urea and lactic acid depends largely on the severity of the cracked heels and the patient’s skin sensitivity. Urea, particularly in higher concentrations, is often preferred for treating severe cases of cracked heels due to its dual-action of hydration and exfoliation. For diabetic patients, urea-based treatments are generally safe when used appropriately and can help maintain the skin's natural barrier function, a key concern for this population.

Lactic acid, while a strong exfoliant, may be better suited for individuals with milder cracked heels or for those who experience irritation with urea. Diabetic patients with sensitive skin might also benefit from the gentler action of lactic acid, though it may take longer to achieve results compared to urea.

Recommended Strengths for Cracked Heels

• For Urea: The typical strength for treating cracked heels ranges from 20% to 40%. A 20% concentration is often recommended for diabetic patients to avoid irritation while still providing effective hydration and exfoliation.
• For Lactic Acid: A 10% to 12% concentration is generally recommended for dry, cracked heels. Diabetic patients should start with lower concentrations to ensure tolerance and reduce the risk of irritation.

Clinical Research Findings

The available clinical evidence indicates that both urea and lactic acid are effective in treating dry skin conditions like xerosis and cracked heels. However, urea tends to outperform lactic acid in terms of hydration, callus reduction, and the healing of more severe heel fissures, especially at higher concentrations (20% to 40%).

For diabetic patients, urea is generally better tolerated and provides greater improvements in skin barrier function without increasing the risk of irritation or injury. Lactic acid, while effective for exfoliation and mild cases of cracked heels, may not be as potent as urea for severe xerosis or fissured skin. Additionally, lactic acid is more likely to cause irritation in sensitive or broken skin, particularly at higher concentrations.

This comparative research underscores the importance of tailoring treatment to the severity of cracked heels and the patient’s underlying conditions, such as diabetes, to maximize benefits and minimize potential side effects.

SkinIntegra’s Rapid Crack Repair Cream combines 25% urea with lactic acid to promote a synergistic effect and achieve faster and safer outcomes in patients with cracked heels.

SkinIntegra is formulated to rapidly heal cracked heels without causing irritation. Its patented formula features 25% urea, a recommended urea strength for moisturization and exfoliation, and lactic acid, an alpha-hydroxy acid that is also used as a peeling agent, but with added humectant benefits that can promote healing. It is specifically designed to heal cracked heels while reducing potential side effects by avoiding salicylic acid to advance patient care and well-being. SkinIntegra prioritizes using natural ingredients without fragrance or dyes and incorporates hyaluronic acid and other barrier renewing ingredients that are skin compatible, which helps the skin retain moisture and stay hydrated without breaking down the surrounding tissue. 

SkinIntegra’s Rapid Crack Repair is clinically proven to work faster with less risk of irritation than a urea 40% cream. It is especially well suited for individuals with diabetes who experience greater skin sensitivity and are more prone to infections.

Conclusion

Both urea and lactic acid are effective treatments for dry, cracked heels, offering distinct benefits depending on the severity of the condition and individual skin sensitivity. Urea is often the preferred choice for more severe cases, offering potent exfoliation and hydration, while lactic acid provides a gentler option for those with milder symptoms or sensitive skin. Diabetic patients, in particular, should take special care when choosing a treatment, as their skin is more prone to complications. Ultimately, consulting with a healthcare provider or podiatrist can help determine the most appropriate treatment plan, especially for individuals with underlying conditions like diabetes.

By understanding the strengths and limitations of these agents, patients can take proactive steps to heal their cracked heels and maintain healthy, smooth skin.