What is Pitted Keratolysis?

Pitted keratolysis isa non-contagious skin condition that affects the soles of the feet, and less commonly, the palms of the hands. It is caused by a bacterial infection of the skin, and may give off an unpleasant odour.

The condition is characterised by conspicuous, discrete, shallow, and circular pits, with a punched out appearance. This appearance is due to the action of the proteolytic enzymes, produced by the bacteria which digest the keratin, the tough protein which gives resilience to the skin.

Pitted keratolysis is mainly caused by coryneform bacteria, though some other bacteria have also been isolated from the lesions.

What are the Signs/Symptoms?

The pits at times join together at places to produce larger erosions, the result being a greenish or brownish hue that is sometimes seen within and around them.

The ailment is often associated with excessive sweating of the palms and soles. The maceration and bacterial digestion of the keratin produce a foul smell; irritation, however, is minimal. At times though, soreness, burning sensation or itching may be presenting features. But beware… soaking feet in water for 15 minutes could result in swelling and accentuation of the pits.

Locations 

The most common locations include:

• Pressure-bearing sites on the soles of the feet, especially the heels
• Non-pressure bearing sites on the soles of the feet
• Palms of the hands
• Under the toes, where superficial erosions can be seen.

Who’s At Risk?

 It can occur in people of any race, any age, and either sex, although it is more common in males. But generally athletes and military personnel tend most to develop this. Conditions that make people more likely to develop pitted keratolysis include:

• Sweaty feet
• Hot or humid weather
• Unventilated (occlusive) footwear, such as rubber boots or vinyl shoes.

How to Prevent It?

Keeping the feet as dry as possible is important. But as well, try to observe the following as far as possible:

• Wearing of absorbent cotton socks and changing them frequently.
• Wearing of wool socks, which may wick moisture away from the foot.
• Washing your feet with antibacterial/antiseptic/antifungal soap daily.
• Minimising the use of tight-fitting, occlusive footwear (try sandals if possible).
• Avoiding the wearing the same pair of shoes 2 days in a row.
• Non-sharing of footwear or towels with others.

Diagnosis and Treatment

Usually clinical appearance is sufficient to make a confident diagnosis of pitted keratolysis.  However, a biopsy can be done for confirmation. If attempts to minimise moisture do not improve the condition, make an appointment with a dermatologist or another physician.

Treatments Your Physician May Prescribe

• Prescription-strength antiperspirant containing aluminum chloride
• Prescription antibiotic lotion
• Antifungal cream
• Prescription oral antibiotics
• Injections in severe cases.

With some combination of these treatments, the skin lesions and odour of pitted keratolysis usually disappear within 4 weeks.