- Clinical science
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 and/or chest. 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 of the hyphae and spores on KOH preparation of skin scrapings. Antifungal topical medications such as selenium sulfide and ketoconazole 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.
- Occurs worldwide, with a higher incidence in tropical climates
- More prevalent in healthy individuals 21–30 years of age 
Epidemiological data refers to the US, unless otherwise specified.
- Risk factors
- Round, well-demarcated macules that reveal a fine, subtle scale with gentle scraping that can coalesce into patches (which may have irregular shapes)
- Colors vary
- Lesions do not tan in the sunlight, because of which they are more commonly noticed in the summer.
- Milder pruritus (compared to dermatophyte infections)
- 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.
- Pityrosporum folliculitis: an infection of hair follicles caused by Malassezia spp. that typically manifests as pruritic, papulopustular eruptions. 
The differential diagnoses listed here are not exhaustive.
- Topical antifungals (first-line therapy) 
- Oral antifungals 
- 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.