Case Study : Dermatology

59. Pitted Keratolysis

Gratefully sourced with permission from Photo Rounds in The Journal of Family Practice

59. Malodorous itchy feet

A 16-year-old boy presented to his family physician (FP) with malodorous feet and some itching between his toes.

He was somewhat embarrassed to take off his shoes, but the FP convinced him that his feet must be examined to make the diagnosis and provide appropriate treatment.

The boy removed his shoes and the FP examined his feet while wearing gloves.

The boy played soccer on his high school team and was in otherwise good health

Diagnosis: Pitted Keratolysis

This patient was suffering from pitted keratolysis and interdigital tinea pedis.


Pitted keratolysis is caused by the bacterium Kytococcus sedentarius.

Like tinea pedis, moist and sweaty feet provide a great environment for growth of this organism.

The patient admitted to having sweaty feet—especially while playing soccer for hours.

He also didn’t use shower shoes in the gym shower.

In pitted keratolysis, the bacteria live on the dead cells of the stratum corneum of the sole and form visible pits.

In interdigital tinea pedis, the skin between the toes is white in appearance.

The FP recommended that the patient wear shower shoes and change his socks during the day if they become sweaty.

He also prescribed topical 2% erythromycin solution to apply twice daily to the area with visible pits.

In addition, the FP recommended that the patient buy over-the-counter topical terbinafine cream and apply it between the toes once or twice daily—especially after drying his feet well after a shower.


A month later, both infections were clear.


Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Usatine R, Reppa R. Tinea pedis. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:799-804.

Copyright  © 2017 Frontline Medical Communications Inc., Parsippany, NJ, USA. All rights reserved. Unauthorized use prohibited.The information provided is for educational purposes only. Use of this Web site is subject to the medical disclaimer and privacy policy.

Ireland notes.png

In the ROI, 2% erythromycin + isotretinoid gel is available in Ireland as Isotrex

and 4% erythromycin + 1,2% zinc acetate topical solution is available in Irelandas Zineryt

Terbinafine cream is available in Ireland as Lamisil

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