Black heel, medically known as calcaneal petechiae or talon noir, is a common and harmless skin discoloration appearing on the back or sides of the heel. The name, which translates from French to “black nail,” accurately describes the dark, speckled appearance. While frequently seen in athletes and highly active individuals, it can affect anyone whose feet experience repeated friction or trauma. This article explains the cause of this benign condition, details effective home treatments for removal, and provides practical strategies for preventing its recurrence.
What Causes Black Heel?
Black heel results from repeated, low-level trauma applied to the skin of the heel, creating a shearing force. This force occurs when the foot slides or rotates slightly within a shoe during activities like running, jumping, or abrupt stopping. The continuous movement causes the outer layer of skin (the stratum corneum) to shift relative to the tissue underneath.
This micro-trauma damages the delicate capillaries just beneath the skin’s surface. As these vessels rupture, small amounts of blood leak out and become trapped within the keratinized cells of the epidermis. The resulting discoloration is a cluster of micro-hemorrhages, appearing as pinpoint, dark brown, blue, or black spots. The dark color is simply dried blood within the skin layers, not dirt, a bruise, or a mole.
Immediate At-Home Remedies
The spots associated with black heel are not a medical concern and will naturally fade as the skin renews itself, typically within four to six weeks once the causative activity is stopped. To expedite the process, focus on removing the superficial skin layer containing the trapped blood. The most direct method for speeding up resolution involves gentle exfoliation.
Manual exfoliation using a pumice stone or a foot file helps shed the outermost layer of dead skin cells. This should be done carefully after soaking the feet in warm water for ten to fifteen minutes to soften the keratinized tissue. Scrub gently, focusing on removing the pigmented surface layer without causing pain or irritation. Over-exfoliating can create new trauma, potentially worsening the condition.
Chemical exfoliation offers another effective approach using ingredients designed to dissolve the bonds between skin cells. Alpha Hydroxy Acids (AHAs) or Beta Hydroxy Acids (BHAs), such as salicylic acid or urea-based foot creams, accelerate cell turnover. These products loosen the dead cells, allowing the pigmented layer to shed more quickly. For an existing black heel, consistent application of a high-concentration urea cream (20-40%) under occlusion, such as a sock, can be highly effective over several days.
Unlike fungal infections, which require antifungal creams, black heel is purely mechanical trauma requiring physical or chemical removal of the stained layer. If the spot is large or persistent, a simple diagnostic technique involves lightly scraping the surface; if the dark color is removed, it confirms the diagnosis of black heel.
Preventing Recurrence
Preventing the return of black heel requires minimizing the friction and shearing forces that initially caused the trauma. The first step involves careful attention to footwear, ensuring that athletic shoes fit correctly and securely. Shoes should have a stable heel counter—the rigid cup at the back of the shoe designed to cradle the heel bone and limit movement.
Lacing techniques also play a significant role in securing the foot and preventing heel slip inside the shoe. Utilizing a “heel lock” or “runner’s knot” lacing pattern effectively pulls the heel deeper into the heel counter, reducing the vertical and lateral movement that causes friction. Replacing old shoes that have lost their internal structure or cushioning is a practical preventative measure.
The right sock choice provides a substantial barrier against shearing forces. Moisture-wicking synthetic socks (polyester or merino wool) are preferable over cotton, as they draw sweat away from the skin, preventing it from becoming soft and susceptible to friction. Wearing two pairs of thinner socks, known as the double-sock technique, is highly effective because friction occurs between the two sock layers instead of between the sock and the skin.
For individuals who experience persistent issues, specialized padding or lubrication can be applied directly to the heel. Products like anti-friction balms, petroleum jelly, or specialized foot powders decrease the coefficient of friction between the skin and the sock. Applying a piece of moleskin or a hydrocolloid bandage directly over the affected area before activity provides a physical cushion and barrier, absorbing the shear stress.
When to Consult a Dermatologist
While black heel is a benign condition, a medical opinion should be sought to rule out more serious diagnoses. The primary concern is differentiating calcaneal petechiae from acral lentiginous melanoma, a type of skin cancer that can appear on the soles or heels. A simple at-home test is pressing on the spot; black heel (which is trapped blood) will not blanch or lighten, but a melanoma will have features that change over time.
Consult a healthcare provider if the discoloration is raised, bleeds spontaneously, or is accompanied by pain, swelling, or redness. Any lesion that changes rapidly in size, shape, or color, or one that fails to fade within a few weeks after stopping the causative activity, warrants a professional examination. A dermatologist can confirm the diagnosis quickly, often by using a dermatoscope or by lightly scraping the top layer of skin, which removes the pigment in cases of black heel.