• Clinical science

Tinea versicolor

Abstract

Tinea versicolor (pityriasis versicolor) is a benign superficial skin infection that occurs most often in young adults during hot and humid weather and is most commonly caused by the fungi Malassezia globosa and Malassezia furfur. The infection is characterized by finely scaling, hypopigmented or hyperpigmented macules on the trunk. Patients often become aware of the disease after sun exposure because the lesions do not tan and become more visible against the recently tanned surrounding skin. Diagnosis is commonly made clinically, but can be confirmed with the “spaghetti and meatballs” pattern on KOH preparation of skin scrapings. Antifungal topical medications such as selenium sulfide and miconazole are considered first-line treatment. Oral fluconazole and itraconazole may be considered for those with severe, widespread, or refractory disease. Lesions will resolve completely over time, but recurrences are common.

Epidemiology

  • Occurs worldwide, with a higher incidence in tropical climates
  • More prevalent in healthy individuals of 15–24 years of age

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

References:[2][3][1]

Pathophysiology

Widely accepted mechanism: pathogens infect the stratum corneumdegrade lipids → produce acids that damage melanocytes and cause inflammationhypopigmentation or hyperpigmentation of skin, respectively

References:[4][5]

Clinical features

  • Round, well-demarcated macules that reveal a fine, subtle scale with gentle scraping → can coalesce into patches (which may have irregular shapes)
  • Colors vary from hypopigmentation, pityriasis versicolor alba, to hyperpigmentation, pityriasis versicolor rubra, and from white to brown or reddish brown.
  • Lesions do not tan in the sunlight.
  • Mild pruritus
  • Common sites are the trunk and chest, but the neck, abdomen, upper arms, and thighs may also be affected.

Patients often become more aware of the lesions after exposure to sunlight because the surrounding skin tans while the lesions do not!


References:[1]

Diagnostics

  • Usually a clinical diagnosis
  • Confirmatory test: potassium hydroxide (KOH) preparation of skin scrapings demonstrates the "spaghetti and meatballs" pattern
  • Ultraviolet light (Wood's lamp); may reveal a coppery-orange or yellow fluorescence (∼ 30% of cases)

References:[6][3][1][5]

Differential diagnoses

References:[6][3][1]

The differential diagnoses listed here are not exhaustive.

Treatment

  • Topical antifungals (first-line therapy)
  • Oral antifungals
    • Reserved for disease that is severe, widespread, or unresponsive to topical therapy to reduce the possible risks of systemic medication (not typically used in children)
    • Oral fluconazole or itraconazole are the preferred oral agents.
    • Other oral antifungal agents may also be effective. However, their side effects are a concern: Oral ketoconazole, for instance, is contraindicated due to risk of serious side effects (liver and adrenal damage).
  • 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.

References:[3][1][5][7]