Tinea versicolor On the Web
American Roentgen Ray Society Images of Tinea versicolor
Tinea versicolor or pityriasis versicolor is a common skin infection caused by the yeast Malassezia furfur (formerly termed Pityrosporum ovale). This yeast is normally found on the human skin and only becomes troublesome under certain circumstances, such as a warm and humid environment.
The symptoms of this condition include:
- Generally oval or irregularly-shaped spots of 1/4 to 1 inch in diameter, often merging together to form a larger patch
- Occasional fine scaling of the skin producing a very superficial ash-like scale
- Pale, dark tan, or pink in color, with a reddish undertone that can darken when the patient is overheated, such as in a hot shower or during/after exercise
- Sharp border
These spots commonly affect the back, underarm, upper arm, chest, lower legs, and neck. Occasionally it can also be present on the face. The yeasts can often be seen under the microscope within the lesions and typically have a so called "spaghetti and meat ball appearance" as the round yeasts produce filaments.
In people with dark skin tones, pigmentary changes such as hypopigmentation (loss of color) are common, while in those with lighter skin color, hyperpigmentation (increase in skin color) are more common. These discolorations have led to the term "sun fungus".
Tinea versicolor must be differentiated from other diseases presenting with an erythmatous, scaly, annular and pruritic rash. The differentials include the following:
|Name of superficial infection||Clinical presentation||Extension to hair follicle||Fungus(i)||Systemic disease||KOH preparations||Morphology in tissue sections|
|Tinea or ringworm||Round lesions with scaly border, accompanied by pruritis and burning||Yes; when suppurative known as kerion, when chronic known as Majocchi's granuloma||Dermatophytes (Epidermophyton spp., Trichophyton spp., Microsporum spp.)||Very rare but can invade the dermis and soft tissues, causing mycetomas||Hyphae with or without septations||Hyphae cannot be visualized in the keratin with H&E, special stains are needed|
|Tinea versicolor||Hypo and hyperpigmentation in patients with oily and sweaty skin, fine scales when scratching||Yes, known as Pityrosporum folliculits||Malassezia spp.||Systemic infections may occur in premature neonates receiving parenteral nutrition and in other immunosuppressed hosts||Yeasts and hyphae (“spaghetti and meat balls”)||Faintly basophilic hyphae in the stratum corneum|
|Tinea nigra||Brown to black macule, usually on palms, with some scaling||No||Phaeoannellomyces werneckii||Not described||Darkly pigmented, septated, and branching hyphae||Pigmented hyphae in the stratum corneum|
|White piedra||Creamy-white, small, soft nodules in hair shafts||No||Trichosporon spp.||Immunosuppressed patients may have lung infiltrates, renal involvement, and fungemia||Septate hyphae perpendicular to hair shaft||Not used for diagnosis|
|Black piedra||Hard dark nodules in hair shafts||No||Piedraia hortae||Not described||Collections of crescent ascospores surrounded by pigmented hyphae||Not used for diagnosis|
|Superficial candidiasis||Intertrigo, chronic paronychia, onychodystrophy, cheilitis||Yes||Candida spp.||Yes, particularly in patients with AIDS and depending on the level of immunosuppression||Yeasts, pseudohyphae may be observed||Fungal elements may be seen through the biopsy, vascular invasion must be determined|
Tinea versicolor is a common condition. It is estimated that 2 to 8% of the population of the United States has it. This skin disease commonly affects adolescents and young adults, especially in warm and humid climates. It is thought that the yeast feeds on skin oils (lipids) as well as dead skin cells.
Treatments for tinea versicolor include:
- Topical antifungal medications - containing either 2.5% selenium sulfide (Selsun® shampoo in UK, but not Selsun Blue which contains only 1%) or 2% ketoconazole (Nizoral® ointment and shampoo) applied to dry skin and washed off after 10 minutes, repeated daily for 2 weeks. Other topical antifungal agents such as clotrimazole, miconazole or terbinafine are less widely recommended. Additionally, hydrogen peroxide has been known to lessen symptoms, and on certain occasions, remove the problem.
- Oral antifungal prescription only medications include 400 mg of ketoconazole or fluconazole in a single dose, or ketoconazole 200 mg daily for 7 days, or itraconazole 400 mg daily for 3-7 days. The single-dose regimens can be made more effective by having the patient exercise 1-2 hours after the dose, to induce sweating. The sweat is allowed to evaporate, and showering is delayed for a day, leaving a film of the medication on the skin.
- Recurrence is common and may be reduced by intermittent application of topical agents (such as tea tree oil) or adding a small amount of anti-dandruff shampoo to water used for bathing.
- Tinea versicolor