Excessive dryness and wetness
The most frequent cause of heel fissures (cracks) is xerosis (dry skin). This is often complicated if the skin around the heel has an overlying thickened callus. Thickened calluses cannot flex easily with underlying layers of skin, so the mechanical impact of your heel strike in walking can often trigger cracking. Ground reaction forces on callused heel cracks will displace the cracks deeper, often resulting in painful bleeding.
Dry skin is not the only culprit; both extremes of dryness and wetness can affect the skin’s intrinsic tensile strength. Excessive sweating can result in soggy skin, which will slide – setting up friction that can trigger callus formation. Perpetually damp callused heels have poor tensile strength and can just as easily crack.
Fungal infection
Secondary to very dry or excessively damp skin, fungal infection can further weaken the skin, causing fissures.
Mechanical factors
Standing for long periods of time on hard surfaces can predispose heels to crack. High impact sport, such as running, will increase the ballistic effect on your heels. Increased pressure on your heels from carrying weight in excess of your normal body weight, whether through being overweight or in early motherhood carrying infants, or constant excessive load carrying in any form may lead you to develop cracked heels. Biomechanical reasons include heel spurs (bony outgrowths of the heel bone), malalignment of the metatarsal bones, flat or high arched feet and abnormalities of gait (the way in which you walk).
Metabolic reasons
Some medical conditions can lead to skin becoming very dry, for example, psoriasis and eczema. Dry skin due to reduced sweating can occur due to neuropathy – damage to fine nerves of the autonomic nervous system in such illnesses as diabetes mellitus.
An underactive thyroid will decrease metabolic rate, leading to a decrease in sweating and result in dryness of the skin. Spinal, pelvic, thigh, leg or ankle surgery or trauma can affect the nerves controlling sweat gland function in the feet.
What should I know about footwear to prevent cracked heels?
Look for a good fit at the heel area. Remember that pressure or friction is the cause of calluses on the heels. In the case of open-backed styles, poor fit may result in part of your heel constantly stepping on the edge of the shoe or sandal.
Styles that improve fit are those that grip around the heel (either closed heel or strap), plus a fastening or closure across the instep of the foot.
Shoes that are too wide will cause shearing stress under the foot as it slides around in the shoe, causing calluses to build up under the foot. Look for a style with suitable fastening across the instep of a shoe to prevent the slide.
Shoes that are too narrow in the heel will pinch the edges of the heel, causing hard ridges of calluses.
Thin-soled shoes or shoes without innersole cushioning will transfer all the ground reaction forces of hard impact with man-made surfaces directly into the bones of your feet, causing the stimulus for callus formation.
Shoes made from leather and breathable materials are best, since they neither contribute to dehydration nor excessive sweatiness of the feet.
What can I do about cracked heels?
Avoid footwear in which your foot will slide around, so as to avoid the friction that stimulates callus formation. Buy shoes and sandals with shock-absorption in the outer soles or inner soles or both. Heels can dehydrate to greater or lesser degrees in open-backed footwear in the hot South African climate, so maintain adequate hydration by means of heel balm preparations.
Avoid the use of excessively hot water when bathing or showering – it may cause your feet to perspire, resulting in loss of valuable moisture from underlying skin layers.
Keep skin supple. Any generalised gradual build-up of hard skin, such as that caused by walking barefoot outdoors, can be removed by means of daily light abrasion – using a pumice stone or fine grit foot file – together with regular daily use of a heel balm containing urea. Always moisturise at the end of the day; applying heel balm in the morning could cause your feet to perspire excessively inside your shoes. Consult a podiatrist if deeper cracks are present.
The urea in your heel balm is the important ingredient that weakens the keratin bond, allowing moisturisers to penetrate below the keratin level, keeping skin supple. (N.B. Urea is formulated in a laboratory so it is both halaal and kosher). Foot creams that do not contain a keratolytic ingredient, such as urea, will never penetrate the stratum corneum layer (outer heel skin) satisfactorily.
If your feet are always moist or damp, you may need to use a daily antiperspirant in the morning on the soles of your feet to dry them sufficiently so that dry abrasion will work. Never use antiperspirants if cracks are already present. Severe perspiration levels respond well to medical strength antiperspirants which are available on consultation with your podiatrist.
Foot care products containing tea tree can prevent fungal infection since studies have shown that tea tree has antifungal, antiviral and antiseptic properties.
Never pick or peel skin on thickened heel calluses. This will tear across layers, leaving uneven patches that act as a haven for bacteria, and may cause further cracking. Never attempt bathroom surgery on cracked heels or heel calluses. If cracks bleed, you may use adhesive dressings or gauze to relieve pressure on the heels until you can consult a podiatrist.
Never use any form of chemical pads or metal objects, such skin ‘graters’, scissors or blades, to remove calluses. Your best efforts will result in an uneven surface – that alone will stimulate more callus formation by creating micro-overload areas. You may risk self-injury and infection. All cracked heels are best treated by a podiatrist.
When should I consult a podiatrist about cracked heels?
When dry heels and/or callused cracked heels fail to respond to light abrasion, combined with daily use of a heel balm containing urea, that’s the time to see your podiatrist. A podiatrist will painlessly and smoothly remove the cracks. He or she may apply various temporary pads to relieve the pressure. Permanent solutions may include special heel pads or heel cups to stop sideways heel expansion, recommendation of appropriate shoes, or special accommodative inner soles to relieve pressure, or orthotics to correct or accommodate functional problems of your foot structure or gait.
If calluses only seem to appear on one side of your heels, or more so on one side of your heels than another, you may have an anatomical or gait imbalance. These are common problems in biomechanics, which podiatrists are trained to treat. Podiatrists are qualified in dermatology of the foot, so consult a podiatrist should you have psoriasis or eczema.
Ask your podiatrist to simply assess your shoes and your heels if you’re uncertain.
Untreated cracked heels can result in complications; the most common is development of other callused areas under the foot as you change your posture and/or gait to avoid further pressure on your cracked heels. You may even develop knee, hip or back pain. Cracks may deepen to the dermal layer, resulting in bleeding. Open cracks can become infected with viral, fungal and/or bacterial infection. In diabetes patients and persons suffering from poor circulation, healing is slower so cracked heels should be avoided. Always seek professional help.
Call the South African Podiatry Association on 0861 100 249 or log on to www.podiatrist.co.za for the details of your nearest podiatrist. Remember that podiatrists are registered with the Health Professions Council, and you may, therefore, claim their fees from your medical scheme.