OSCE — Becker's naevus

Brief (to candidate)

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

Clinical context

Becker's naevus is a benign, androgen-dependent hamartoma of skin presenting as a large, unilateral, light-brown to dark-brown patch with overlying hypertrichosis on the shoulder, upper chest, or upper back, first appearing at puberty. Histology shows increased basal-layer melanin, epidermal acanthosis and papillomatosis, and arrector pili (smooth muscle) hyperplasia — there are no naevus cells. The course is benign with no malignant potential; management is reassurance, with Q-switched laser for pigmentation and long-pulsed laser for hair if cosmesis is desired. Becker's naevus syndrome is the rare association with ipsilateral breast hypoplasia, skeletal anomalies and limb asymmetry.

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]