Pitted keratolysis is characterized by circular pits with a punched out appearance. It is seen on the soles, and, at times, on the palms as well. Pitted keratolysis is mainly caused by coryneform bacteria, though some other bacteria have also been isolated from the lesions, such as the Micrococcus sedentarius, Actinomyces keratolytica and Dermatophilus congolensis.
The punched out appearance is due to the action of the proteolytic enzymes produced by the bacteria which digests the keratin, the tough protein which gives resilience to the skin.
What are the Signs and Symptoms of Pitted Keratolysis?
Superficial erosions are seen on the soles and under the toes in pitted keratolysis. Both sides are equally affected. Conspicuous, discrete, shallow and circular pits with a punched-out appearance are the hallmark of pitted keratolysis. The pits join together at places to produce larger erosions. Sometimes a greenish or brownish hue is seen within and around the pits. Pitted keratolysis is often associated with excessive sweating of the palms and soles (palmoplantar hyperhidrosis). The maceration and bacterial digestion of the keratin produces a foul smell. Irritation is minimal. At times, though, soreness, burning sensation (burning feet) or itching may be presenting features of pitted keratolysis.
Soaking feet in water for 15 minutes results in swelling and accentuation of the pits.
Erythrasma and fungal infections of the feet have to be ruled out in cases of pitted keratolysis.
Why are Some People more Prone for Pitted Keratolysis?
Increased sweating, excessive washing, prolonged use of occlusive footwear and so on predispose individuals to pitted keratolysis. Diabetics and those on immunosuppressive medications are also more prone for pitted keratolysis.
How to Prevent Pitted Keratolysis?
Treatment of excessive sweating of the palms and soles is the single most important preventive measure in pitted keratolysis. Use of cotton socks, antibacterial or antifungal dusting powders and airy, loose fitting shoes help prevent recurrent infections. Early treatment is also of paramount importance in preventing recurrences. It is also advisable to replace the shoes after a course of treatment.
How to Diagnose Pitted Keratolysis?
Usually clinical appearance is sufficient to make a confident diagnosis of pitted keratolysis. Gram’s staining of the scraping and culture of the scraped material on brain heart infusion agar helps in clinching the diagnosis.
How to Get Rid of Pitted Keratolysis?
Treatment of pitted keratolysis is simple and straight forward. Initial step of course is to treat any coexisting palmoplantar hyperhidrosis. Most of the time, a two to three weeks’ course of topical fusidic acid ointment is sufficient to get rid of the pitted keratolysis. In recurrent or severe cases, a two weeks’ course of oral erythromycin or azithromycin will clear the pits completely. Topical clotrimazole is also helpful to get rid of pitted keratolysis.
References:
- Rook’s Textbook of Dermatology, 7th Edition, 2004
- Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology, Fifth Ed, 2005
Disclaimer
The information given in this article is for educational purposes only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or Suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.
Hanish Babu - Dr.Hanish Babu, MD is a dermatologist and a feature writer on Suite101.com with more than 200 articles related to skin diseases on the ...
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