Pitted keratolysis is a descriptive title for a skin condition affecting the soles of the feet.
It affects those who sweat profusely (hyperhidrosis) especially if they wear occlusive shoes or boots for long periods.
The result is very smelly feet, due to infection of the soles. Either the forefoot or the heel or both become white with clusters of punched-out pits. The appearance is more dramatic when the feet are wet. Very rarely, the fingers are similarly affected. There is a variant of pitted keratolysis where there are more diffuse red areas on the soles.
Image provided by Dr S Janjua
What is the cause of pitted keratolysis?
Pitted keratolysis is caused by several bacterial species, including corynebacteria, Dermatophilus congolensis, Kytococcus sedentarius, actinomyces and streptomyces.
In moist conditions, the bacteria proliferate. The pitting is due to destruction of the horny cells (stratum corneum) by protease enzymes produced by the bacteria.
The bad smell is due to sulfur compounds produced by the bacteria.
How is the diagnosis of pitted keratolysis made?
Pitted keratolysis is usually diagnosed clinically. Swabs may be helpful to identify causative organisms, and skin scrapings are often taken to exclude fungal infection. The diagnosis is sometimes made by skin biopsy revealing characteristic histopathological features of pitted keratolysis.
Treatment of pitted keratolysis
It will quickly recur unless the feet are kept dry.
- Wear boots for as short a period as possible
- Wear socks which effectively absorb sweat i.e. cotton and/or wool
- Wear open-toed sandals whenever possible
- Wash feet with soap or antiseptic cleanser twice daily
- Apply antiperspirant to the feet at least twice weekly
- Do not wear the same shoes two days in a row – dry them out
- Do not share footwear or towels with others.