Pitted Keratolysis

Skin and Nail Conditions· Also known as: keratolysis plantare sulcatumUpdated Nov 2026

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, November 2026

At a Glance

Pitted keratolysis is a bacterial infection of the soles of the feet. It stays in the thick outer layer of skin and leaves small, crater-like pits. It is described as common and is found around the world, especially in warm places and in people whose feet spend long periods in enclosed shoes. Many people notice sweaty feet and a strong smell. It is not contagious, and with effective antibiotic treatment the outlook is excellent: the pits and the smell can clear within 1 month.

What is it?

Pitted keratolysis is a shallow infection of the skin on the soles of your feet. It is caused by bacteria that live in the thick outer layer of skin (the stratum corneum). The bacteria are mainly a type called Corynebacterium. Other bacteria, including Kytococcus sedentarius and Dermatophilus congolensis, are also named as causes.

The bacteria break down keratin, the tough protein that makes up this outer skin. This leaves small pits that look like tiny craters. The skin around the pits is usually not red or inflamed.

The condition is almost always found on the soles. It is not contagious, so you can't catch it from someone else by touch.

Who does it affect?

Pitted keratolysis is described as common and is found worldwide. It turns up more often in warm climates and in people whose feet are shut in enclosed shoes for long stretches. How many people have it isn't clear yet, because reliable figures aren't available.

It is commonly reported in males, and in jobs that mean wearing closed, airtight footwear. Examples are soldiers, sailors, industrial workers and farmers. It is also described in active people, because sport can leave feet hot and wet.

Signs and symptoms

The main sign is a group of small, crater-shaped pits on the soles. They often start on the parts that take your weight, such as the pads of the toes, the ball of the foot and the heel. The spaces between the toes can be affected next. Often both feet are involved.

Most people also have sweaty feet and a distinctive, unpleasant smell. The skin can feel slimy or soft. Some people have itching or pain, though others have no symptoms apart from the pits and the smell.

In more serious cases the pits can join up into larger, irregular patches or grooves of broken skin, with or without redness.

Pitted keratolysis itself is a mild, shallow infection. But foot skin infections of any kind that don't improve can sometimes spread deeper, to form an abscess (a pocket of pus) or an infection in the bone (osteomyelitis).

Some signs point to something more serious than pitted keratolysis, especially in people with diabetes. Nerve damage and reduced blood flow can hide foot injuries and slow healing. These signs include:

A cut, blister or wound on the foot that isn't healing, or skin that turns red, warm or painful. These can mean infection.
Red streaks or pain moving up the leg. This can mean an infection is spreading, and left untreated it could lead to sepsis (a dangerous reaction of the body to infection).
Feeling cold, shivery, shaky and unwell when you have a foot wound. This can mean sepsis is developing.
Severe pain, or a foot that suddenly turns cold or numb. This can point to infection, poor blood flow or a serious foot problem called Charcot foot.
A black, smelly foot infection. This can be a sign of gangrene (dead tissue).

What causes it?

The bacteria are normally present on skin, but they multiply when conditions suit them. Three things help them thrive: a rise in the skin's surface pH (how acidic or alkaline it is), heavy sweating, and feet that stay shut in for a long time. Heavy sweating (hyperhidrosis) is described as the most important of these.

As the bacteria multiply, they make enzymes that break down the keratin in the thick outer skin. That is what creates the pits. The smell comes from sulphur-containing chemicals the bacteria produce.

How is it diagnosed?

Your podiatrist can usually recognise it by looking at your feet and asking about your symptoms. Sweaty, irritated soles with many small pits are the typical picture, often along with the smell.

It can look different from person to person, especially on different skin tones, which can make it harder to spot. Your podiatrist may also consider other conditions of the sole, such as athlete's foot (tinea) and plantar warts.

Treatment

Treatment aims to clear the bacteria and cut down the moisture they thrive on. The research on treatment is limited. It is mostly case reports and small series, and there is no agreement on the single best approach.

Looking after it at home

Foot hygiene to reduce moisture is described as the starting point of treatment. The aim is to keep your feet from staying damp and enclosed for long periods.

Treatment from your podiatrist

Antibiotics put directly on the skin (topical antibiotics) are the usual first choice. These include erythromycin solution or gel, clindamycin solution, fusidic acid cream and mupirocin cream. They are reported to work well, to be easy to use and to be well accepted by patients.

Benzoyl peroxide, a skin treatment often used for acne, has also been used for pitted keratolysis and foot smell. Both 2.5% and 5% strengths can be used, with similar results and side effects, so the lower strength may be preferable.

Other options

Combining an antibacterial treatment with extra measures, such as antiperspirants, appears to be the most effective approach in the available literature. This makes sense because sweating makes it easier for the bacteria to multiply.

Antibiotic tablets are kept for cases that don't respond to treatment applied to the skin. A foot skin infection that isn't responding can spread deeper, so it needs another look.

Recovery

The outlook is excellent. Pitted keratolysis is treatable, not contagious and not inflammatory. With effective antibiotic treatment, the pits and the smell can clear within 1 month.

The bacteria thrive when your feet are sweaty and enclosed, so these conditions can matter for how quickly it clears.

Preventing it

Limiting long periods of sweaty, enclosed feet targets the conditions that let the bacteria multiply. Heavy sweating on the soles is also linked to a higher risk of skin infections more generally.

It isn't clear yet whether these steps stop the condition coming back.

Frequently asked questions

Is pitted keratolysis contagious?

No. It is described as non-contagious. The bacteria involved are normally found on skin, and they only cause pits when your feet are warm, sweaty and enclosed for long periods.

Why do my feet smell?

The bacteria make sulphur-containing chemicals as they break down the skin. These give pitted keratolysis its distinctive smell. Once the infection is treated effectively, the smell and the pits can clear within 1 month.

Does it only happen to people who wear shoes?

No. It has been reported in people who wear shoes and in people who go barefoot. It is also described in barefoot labourers and farmers, though long periods in wet, enclosed shoes are a common link.