OSCE — Erythrasma

Brief (to candidate)

You will assess a patient with a presentation consistent with Erythrasma.
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.

Clinical context

Erythrasma is a chronic, superficial bacterial infection of intertriginous skin caused by Corynebacterium minutissimum (reclassified by some taxonomic schemes as Kocuria or retained within Corynebacterium), presenting as well-demarcated, reddish-brown, finely scaly macules and patches in the groin, axillae, toe webs, submammary folds and gluteal cleft. The pathognomonic diagnostic sign is coral-red fluorescence under Wood's lamp (UV-A 365 nm) produced by coproporphyrin III. NEET-PG/INICET high-yield topics include differentiation from tinea cruris, candidal intertrigo and inverse psoriasis; the fact that imidazole antifungals are effective against this bacterial infection; and oral erythromy

Candidate tasks

1. Clarify onset, severity, associated features, and red-flag symptoms.
2. State focused examination priorities.
3. List first-line investigations and any named score/criteria.
4. Give immediate resuscitation steps.
5. Outline definitive management with doses/routes where standard.
6. Name complications and disposition (ward / HDU / theatre / discharge safety-net).
7. Mention one special-population modifier (pregnancy, child, elderly, CKD).

Examiner checklist

Model outline

Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use guideline-standard therapy with named agents and doses. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays critical care for non-urgent imaging.^[1]