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Pityriasis versicolor

Last updated: April 3, 2025

Summarytoggle arrow icon

Pityriasis versicolor is a benign, superficial fungal infection most commonly caused by Malassezia furfur or Malassezia globosa. Although the condition occurs worldwide, the incidence is higher in tropical climates. It typically manifests as a well-demarcated, macular rash with round or oval hyperpigmented, hypopigmented, or erythematous lesions that often coalesce. The seborrheic areas of the upper trunk and neck are primarily affected, and the lesions are more noticeable after UV exposure because the surrounding skin darkens while the affected skin does not. Pityriasis versicolor is usually a clinical diagnosis; however, potassium hydroxide (KOH) microscopy of skin scrapings that show hyphae and spores in a characteristic “spaghetti-and-meatballs” pattern confirms the diagnosis. Topical drugs such as selenium sulfide and ketoconazole are recommended for initial treatment; systemic therapy is reserved for extensive or refractory disease. Lesions will resolve completely over time, but recurrences are common.

Pityriasis versicolor was previously known as tinea versicolor, as it was believed to be a dermatophyte infection. Some sources still refer to the condition by its original name.

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Epidemiologytoggle arrow icon

  • Occurs worldwide, with a higher incidence in tropical climates
  • More prevalent in healthy individuals 21–30 years of age [1]

Epidemiological data refers to the US, unless otherwise specified.

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Etiologytoggle arrow icon

Pathogens

  • Malassezia spp. (previously known as Pityrosporum): most commonly Malassezia globosa and Malassezia furfur
  • Dimorphic, lipophilic yeast-like fungi that are part of the normal skin flora
  • Not contagious

Risk factors

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Pathophysiologytoggle arrow icon

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Clinical featurestoggle arrow icon

  • Symmetrically affects the seborrheic areas of the upper trunk (chest, shoulders, upper arms) and neck [4]
  • Rash appears as round or oval macules 1–3 cm in diameter [5]
  • Lesions often coalesce into well-demarcated irregular patches. [4]
  • Color of the lesions may vary in the affected individual (i.e., hypopigmented, hyperpigmented, erythematous) ; [4]
    • Lesions may change color with seasons (e.g., lighter than surrounding skin during summer, darker than surrounding skin in winter).
    • Hypopigmentation is typical in individuals with darker skin. [6]
  • May be mildly pruritic [4][7]
  • Fine, bran-like, subtle scaling if the skin is stretched or gently scraped (evoked scale sign) [4][6][8]

Lesions are more noticeable after UV exposure because the surrounding skin darkens while the affected skin does not. [4]

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Diagnosistoggle arrow icon

  • Diagnosis is usually clinical. [4][9]
  • Wood lamp examination can support the diagnosis; affected areas fluoresce yellow-green. [4][5]
  • KOH microscopy confirms the diagnosis. [4][9]
    • Sample skin scrapings of the affected area.
    • Findings: hyphae and spores arranged in a “spaghetti-and-meatballs” pattern

A fungal culture is usually not performed as the yeast can be part of normal skin flora. [4]

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Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

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Treatmenttoggle arrow icon

Localized disease [4][5]

Extensive or refractory disease [4][5]

Systemic griseofulvin and terbinafine are not effective in treating pityriasis versicolor. [5]

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Prognosistoggle arrow icon

  • The lesions will resolve without any permanent changes within 1–2 months of therapy.
  • Recurrences are common and treatment may need to be repeated intermittently.
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