Pityriasis Versicolor

Chronic superficial fungal infection of the stratum corneum caused by Malassezia species, a lipophilic yeast that is part of the normal skin flora.
Synonym: Tinea Versicolor

Aetiology

  • Causative organism:
    • Malassezia globosa (most common)
    • Malassezia furfur
    • Malassezia sympodialis

Predisposing Factors

  • Hot and humid climate
  • Excessive sweating (hyperhidrosis)

Pathophysiology

  1. Malassezia exists normally as yeast on the skin.
  1. Predisposing factors trigger conversion to the pathogenic mycelial form.
  1. The fungus produces azelaic acid and other metabolites.
  1. These substances inhibit tyrosinase activity in melanocytes.
  1. This leads to hypopigmented or hyperpigmented macules with fine scaling.

Clinical presentation

Skin Lesions

  • Multiple macules or patches
  • Color varies: hypopigmented, hyperpigmented, or erythematous
  • Ill-defined margins
  • Fine, furfuraceous scaling
Hypopigmentation Lesion
Hypopigmentation Lesion
Hyperpigemantation Lesion
Hyperpigemantation Lesion
 

Distribution

  • Upper trunk (chest and back)
  • Neck
  • Shoulders
  • Upper arms
  • Face (more common in children)

Symptoms

  • Usually asymptomatic
  • Mild pruritus, especially with sweating

Characteristic Sign

  • Scratch sign (Besnier sign): fine scales become apparent after gentle scraping

Investigations

  • KOH 20% Examination
    • Shows characteristic “spaghetti and meatballs” appearance:
      • Short hyphae (spaghetti)
      • Round spores/blastospores (meatballs)
  • Wood’s Lamp
    • Yellowish or golden fluorescence
    • Not always present

Management

  • 1st line (Topical Remedy)
    • Selenium sulfide 1–2.5% shampoo
      • Apply to affected areas for 10–15 minutes, then rinse
      • Once daily for 3 days → can be repeated 1 week later
    • Ketoconazole 2% shampoo
      • Used as body wash
      • Leave on for 5–10 minutes, then rinse
      • Once daily for 3 days
    • Topical azoles
      • Miconazole 2x/day for 7 days (face & inguinal region)
      • Terbinafin cr 1% 2x/day for 7 days
  • Systemic Therapy
      • Indications:
    • Extensive involvement
    • Recurrent disease
    • Failure of topical treatment
      • Options:
    • Ketoconazole 200 mg daily for 10 days
    • Itraconazole 200 mg daily for 7 days or 100 mg daily for 14 days
    • Fluconazole 400 mg PO SD or 300 mg once weekly for 2-3 weeks
      • ⚠️ Oral ketoconazole is not recommended due to risk of hepatotoxicity.