Why Do Heels Crack: Three Mechanisms, and What Is on Your Foot in All Three

Look at the shoe rack before the heel. Three different things split the skin at the back of the foot, and what you put on the foot is involved in each of them: an open-backed shoe that lets the heel's fat pad spread until the hard skin around it splits; a closed synthetic shoe that sweats the sole and then dries it; and a fungus that arrives by contact and lives in footwear afterwards. Moisturizer answers the first one. The second is a change of materials, and the third is a diagnosis. Why do heels crack has three answers, and picking the wrong one is why a jar of cream can run out with nothing to show.

Three ways a heel cracks

Pressure on a callus. DermNet's page on cracked heels gives the mechanism in one sentence: Increased pressure on the fat pad under the heel causes it to expand sideways, leading to splitting or cracking of the callus. Hard skin builds at the rim of the heel, the cushion under it spreads when you stand, and the callus, which does not stretch, splits. This is the one a urea cream and a nightly ointment address, and cracked heels is the routine for it.

Occlusion, sweat, and drying. DermNet's page on juvenile plantar dermatosis lists among its causes Excessive sweating ( hyperhidrosis ), which when followed by rapid drying leads to cracking and fissuring, and names what holds the sweat in: The occlusive effect of covered footwear, especially synthetic shoes (eg, nylon or vinyl). Also on the list, Repetitive frictional movements, as the foot moves up and down in a shoe.

A fungus. DermNet's page on tinea pedis describes a form of it that looks like dry, cracked feet: scale covering the sole and sides of the feet, the hyperkeratotic or moccasin type. It does not come from dryness, and it does not respond to moisturizer.

The rest of this page is those three, in order of what you can change.

The shoe: open backs, and synthetic uppers

Two different shoe problems, from two different pages.

The first is the open back. DermNet lists among the contributors to cracking Open-back shoes and sandals, as they provide no support to hold the fat pad under the foot, alongside prolonged standing, especially on hard floors, and excess weight. Can shoes cause cracked heels is answered there: not by drying the skin, but by letting the heel's cushion spread sideways with nothing holding it.

The second is the closed synthetic shoe, and here the source needs its limits stated. Juvenile plantar dermatosis is, as DermNet says, a children's condition: it commonly affects children between the age of 3 and 14 years, with an average age of 8, and Juvenile plantar dermatosis is rarely seen in adults. So the diagnosis is not an adult's, and this page does not hand it to one. What generalizes is the material advice DermNet gives for reducing friction and occlusion, which is written as management for that condition: Wear well fitting shoes, preferably leather, to minimise friction, and Avoid wearing shoes and socks made of synthetic materials.

Cracked heels in children, with shiny red soles and the ball of the foot worst, is the picture DermNet draws of that condition, and its fissures may take many weeks or months to heal. That is a reason to see someone rather than to wait it out.

There is a third shoe mechanism that does apply at any age, and it is an allergy rather than a fabric preference. DermNet lists, among the things juvenile plantar dermatosis is confused with, Allergic contact dermatitis to shoe material, such as rubber accelerant , an adhesive such as paratertiary butylphenol formaldehyde (PTBF) resin , or chromate used as a leather tanning agent. The tinea page names the same family: Contact allergic dermatitis to a component of footwear (such as a rubber accelerant , shoe adhesive , potassium dichromate used as leather tanning agent, or fabric dye ). Note that leather, the material recommended above for friction, is also the one tanned with chromate. If the skin problem tracks a particular pair of shoes, the test that settles it is a patch test, not a different cream, and how that test works is in how to patch test skincare.

The sock

Two sources name fibers, and they do not name the same ones for the same reason, so both go here.

The AAD, writing about dry skin generally: Wearing clothing made of wool or polyester against your skin can also irritate dry, sensitive skin, with the alternative being to wear loose-fitting cotton clothing and a cotton or silk layer under clothes made of rough fabrics. On that reading, wool against already-dry skin is an irritant.

DermNet, writing about reducing friction inside a shoe: Wearing two or more pairs of cotton or woollen socks can also help reduce friction, and Change socks regularly. On that reading, wool is a cushion.

Both are quoted because neither is wrong about the thing it is describing, and nothing here rules between them. What the two agree on is the fiber that appears on both lists without a caveat, cotton, and the one that appears on neither as a solution, synthetic. Best socks for cracked heels is therefore a question about material and about how often they are changed, and no brand is needed to answer it.

When the crack is fungal

Tinea pedis can look like dry, cracked feet. DermNet describes the moccasin form as scale covering the sole and sides of the feet, and the boundary that separates it from the footwear-driven pattern is anatomical: in juvenile plantar dermatosis, Common involvement of the ball of the foot (forefoot) and in some cases the heel; toe-webs and instep are usually spared, helping to distinguish this from tinea pedis. Scale and itch between the toes, especially between the fourth and fifth, is the tinea pattern; skin between the toes that is fine while the weight-bearing sole is cracked points elsewhere.

How it is caught is the part worth being precise about. DermNet: Infection is usually acquired by direct contact with the causative organism , for example using a shared towel, or by walking barefoot in a public change room. A shared towel and a wet communal floor, in that source's words. Shoes appear in its prevention list rather than its transmission list, as somewhere the organism persists: Thoroughly dry shoes and boots and Treat shoes with antifungal powder, alongside Dry feet and toes meticulously after bathing and Avoid wearing occlusive footwear for long periods. That is a narrower claim than the one that circulates about borrowed shoes, and it is the one the source supports.

If it is fungal, which product covers which part of the foot, and for how many weeks, is on four different labels that do not agree; athlete's foot treatment reads them side by side. Cracked heels or athlete's foot is not a question to settle from a photograph. DermNet's diagnostic line for the childhood condition includes Skin scrapings to exclude a fungal infection ( tinea pedis ) and patch tests for contact allergy to footwear may be performed. Scrapings are a clinician's test, and no product is named here for a fungal foot.

When it is a skin condition

DermNet's list of what predisposes a heel to crack is not only dry skin. It names atopic dermatitis, juvenile plantar dermatosis, psoriasis, especially palmoplantar psoriasis, palmoplantar keratoderma, and systemic conditions including diabetes and hypothyroidism. Those are conditions rather than habits, and a heel that cracks against a good routine, or cracks alongside changes on the palms, nails or elsewhere, belongs to that list rather than to the shoe rack. When to see a dermatologist sets out the thresholds.

What to change first

In order of effort, and all from the sources above. Closed-back shoes that fit, rather than backless ones, so the fat pad is held. Leather or another non-synthetic upper rather than nylon or vinyl, so the sole is not sealed in. Cotton socks, changed regularly, with wool as a friction option and a caution about wool against dry skin. Feet dried properly after washing, toes included. And shoes dried between wearings.

Then the routine: a urea cream on damp heels, plain petroleum jelly under socks at night, and a week before judging it. That is cracked heels, which also has the point at which a heel stops being a shopping problem.

When this is a dermatologist's question

Fissures that bleed, or a foot that is hot, red and swelling, which is infection rather than dryness. Scale or itch between the toes, which points at the fungal pattern and needs scrapings rather than a cream. A rash that tracks one pair of shoes, which needs a patch test. A child with shiny, red, cracked soles, since DermNet describes those fissures as taking weeks or months. And anyone with diabetes, at any stage of any of this, since loss of sensation changes what a crack on a foot can become.

The three mechanisms, side by side

	Pressure on a callus	Occlusion and sweat	Tinea pedis
Where it sits	Rim of the heel	Weight-bearing sole, ball of the foot, sometimes the heel	Between the toes, or scale over the sole and sides
What it looks like	Thick callus, splitting	Shiny, glazed, red, fissured	Scaling, often itchy; moccasin pattern on the sole
The shoe's part	Open backs let the fat pad spread	Synthetic, closed uppers hold sweat in	A reservoir to dry and treat, not the usual route of infection
Who	Anyone; standing, weight	Described in children 3 to 14; rarely adults	Anyone
What addresses it	The urea-and-ointment routine	Materials, fit, dry feet	A clinician's diagnosis
Source	DermNet, cracked heel	DermNet, juvenile plantar dermatosis	DermNet, tinea pedis

FAQ

What causes cracked heels? Three different things. Pressure spreading the heel's fat pad until the callus around it splits; sweat held in by closed synthetic footwear and then drying the sole; and a fungal infection whose moccasin form looks like dry, scaly feet. Only the first is a moisturizer problem.

Can shoes cause cracked heels? Yes, in two ways that the sources describe separately: open-backed shoes give the fat pad no support, and closed synthetic shoes hold sweat against the sole. Shoe materials can also cause an allergic dermatitis, for which the test is a patch test.

What are the best socks for cracked heels? Cotton, changed regularly, is the fiber both sources are comfortable with. DermNet suggests two or more pairs of cotton or woollen socks to reduce friction; the AAD notes that wool against dry, sensitive skin can irritate it. Neither names a brand, and neither do we.

Can you catch cracked heels from someone else's shoes? Not cracked heels as such. What is catching is the fungus that can look like them, and DermNet names its usual routes as direct contact, a shared towel, or walking barefoot in a public change room. Shoes are listed as something to dry thoroughly and to treat with antifungal powder, which is a different claim.

Is it cracked heels or athlete's foot? Location helps: the childhood footwear pattern usually spares the toe-webs and the instep, while tinea often starts between the fourth and fifth toes. But scrapings are what settle it, and that is a clinician's test.

Why do my heels crack even though I moisturize? Because moisturizer addresses one of the three mechanisms. If the shoes are backless, the fat pad keeps spreading; if the shoes are synthetic and the feet sweat, the sole keeps cycling between wet and dry; and if it is fungal, the cream is beside the point.

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The heel is where the problem shows, and the shoe rack is where two of the three mechanisms live. Before buying another jar, look at what the foot spends its day inside: whether the back of the shoe holds the heel, what the upper is made of, what the socks are made of, and whether the feet are dry when they go in. Then read cracked heels for the routine, which works on the mechanism the jar is actually for.

Sources

• Cracked heel, DermNet
• Juvenile plantar dermatosis, DermNet
• Tinea pedis (fungal foot infection), DermNet
• Dermatologists' top tips for relieving dry skin, American Academy of Dermatology