A 24-Year-Old Man with Excessively Odorous and Itchy feet

Differential Diagnosis

• Tinea pedis
• Palmoplantar keratoderma
• Clavus
• Pitted keratolysis

Diagnosis

This patient was diagnosed with pitted keratolysis, also known as keratoma plantare sulcatum and ringed keratolysis. This is a noninflammatory bacterial infection of the plantar stratum corneum caused by Kytococcus sedentarius (formerly Micrococcus sedentarius), Dermatophilus congolensis, or species of Corynebacterium or Actinomyces.

Learnings/What to Look for

• Predisposing factors are excessive sweating and prolonged occlusion in a warm, humid environment
• Affected areas are generally asymptomatic, but can emit a foul odor due to the production of isovaleric acid by the bacterial metabolism in the leucine in sweat
• Rarely, pruritis, pain, or burning may be present

Pearls Urgent Care Management and Considerations for Transfer

• Topical antibacterial medications, including erythromycin, clindamycin, mupirocin, fusidic acid, or benzoyl peroxide
• Aluminum chloride 20% may be used to treat excessive sweating, which may be a contributing factor in pitted keratolysis
• Patients should be counseled to wash their feet with soap or antiseptic cleanser twice daily; wear absorbent cotton or wool socks; and to avoid wearing the same shoes on consecutive days

Acknowledgment: Images and case presented by Visual Dx (www.VisualDx.com/JUCM).