• Clinical science



Erythrasma is a skin infection caused by Corynebacterium minutissimum, a part of the normal skin flora. Optimal conditions for bacterial growth are provided by moist skin fold areas. The infection is particularly common in obese individuals with diabetes mellitus. Patients present with well-demarcated erythematous or brown patches with fine scaling and wrinkling in intertriginous areas (e.g., groin, toe webs). The diagnosis is confirmed by coral-red fluorescence under wood lamp examination. Local disease is treated with topical antibiotic therapy, while extensive disease requires systemic antibiotic treatment.



Clinical features

  • Location: intertriginous areas (e.g., toe webs, groin, axilla)
  • Skin lesion: well-demarcated erythematous or brown patches with fine scaling and wrinkling
  • Pruritus is usually absent or mild.



  • Wood lamp examination: coral-red fluorescence
  • Gram stain of skin scrapings: gram-positive rods


Differential diagnoses

Intertrigo (intertriginous dermatitis)

  • Definition: dermatitis that particularly affects skin folds (submammary, inguinal, interdigital)
  • Etiology
  • Clinical features
  • Diagnosis: Secondary infections can be confirmed with microbiological testing.
  • Treatment
    • Uncomplicated intertrigo
      • Topical protective and drying agents (e.g., zinc oxide ointment, petrolatum petroleum jelly , talcum powder, aluminum sulfate)
      • Maintaining dry skin and reducing intertriginous friction (e.g., with cotton or linen cloth)
    • If secondary infection is present: Treatment depends on the organism.


The differential diagnoses listed here are not exhaustive.


  • General: improved skin hygiene, maintaining dry skin (e.g., with cotton or linen cloth)
  • Medical therapy
  • Prognosis: Recurrence is common.


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  • 3. Kibbi AG. Erythrasma. In: James WD. Erythrasma. New York, NY: WebMD. https://emedicine.medscape.com/article/1052532. Updated July 20, 2017. Accessed December 18, 2017.
  • 4. Vakharia P. Intertrigo. In: James WD. Intertrigo. New York, NY: WebMD. https://emedicine.medscape.com/article/1087691. Updated April 28, 2017. Accessed December 1, 2017.
  • 5. Kalra MG, Higgins KE, Kinney BS. Intertrigo and secondary skin infections. Am Fam Physician. 2014; 89(7): pp. 569–73. pmid: 24695603.
last updated 11/09/2018
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