FFinalistSouthampton · 2027
Dermatology
AKT · Dermatology/Infections & infestations

Pityriasis versicolor

Malassezia (yeast) overgrowth of the skin flora

Overview

A common superficial yeast (Malassezia) overgrowth producing fine scaly macules of altered pigment on the upper trunk. The pigment change (hypo- or hyperpigmented, more visible after sun exposure) and fine branny scale are the giveaways. Not contagious.

Recognise

  • Multiple well-defined macules/patches with fine "branny" scale on the upper trunk, shoulders and back
  • Variable colour — hypopigmented (especially after tanning, as the yeast blocks pigment transfer) or pink/brown
  • Mild or no itch; scale is revealed by gently scratching ("evoked scale")

Red flags

  • Widespread or frequently recurrent disease; immunosuppression

Differentials & how to tell them apart

Vitiligocomplete depigmentation (stark white), NO scale, well-demarcated
Pityriasis roseaherald patch + oval lesions along cleavage lines, collarette scale
Pityriasis albaill-defined hypopigmented patches on the face/arms of children with atopy
Tinea corporisannular with an active edge, not multiple branny macules

Clinical image

We can't host this one — the image is DermNet's and their licence doesn't cover us republishing it. Their page for it is free to view.

Pityriasis versicolor — clinical imagesDermNet

Investigations

Clinical; skin scrapings show a "spaghetti and meatballs" pattern (hyphae + spores) on microscopy; Wood lamp may show yellow-green fluorescence.

Management

Topical ketoconazole (or selenium sulfide) applied to the affected skin

  1. 1Topical ketoconazole shampoo (used as a body wash) or selenium sulfide; counsel that pigment change takes months to normalise even after the yeast is cleared.Gate: Warn the patient the pigment difference PERSISTS for weeks-to-months after successful treatment — do not interpret residual hypopigmentation as treatment failure
  2. 2Extensive, recurrent or unresponsive → oral itraconazole; intermittent topical prophylaxis for frequent recurrences.
Topical antifungal (ketoconazole shampoo as a body wash, or selenium sulfide) — first-line; apply to affected areas, leave then wash off
Topical imidazole cream — small areas
Oral itraconazole — extensive or recurrent/unresponsive disease

Key points

The hypopigmentation persists long after cure (the dye is gone but the pigment cells recover slowly). Recurrence is common — prophylaxis helps.

Monitor & prognosis

Clearance of scale; pigment normalises slowly.

Responds well but recurs frequently.

Source: NICE CKS Pityriasis versicolor; DermNet