Background

This common yeast infection of the skin is also known as Pityriasis versicolor. It is caused by Malassezia furfur, an unusual yeast which cannot be cultured. The diagnosis is often made by clinical examination with patients presenting with a scaly, macular or nummular lesion with variable coloration. It commonly occurs on the upper trunk and arms and is chronic and recurrent. Patients with seborrheic dermatitis, hyperhidrosis, and residence in the tropics appear to be at increased risk. A clinical variant is Pityropsorum folliculitis which presents with erythematous follicular papules occurring on the back, shoulders, chest, and upper arms. These pruritic lesions are more common in women over 30 years of age.

The varied coloration of the rash results from the organism producing a dicarboxylic acid which inhibits the enzyme tyrosinase, essential for the production of melanin. The histopathology may be subtle and may show minimal changes. Classically, there are fungal yeast and hyphae present within the stratum corneum creating a spaghetti and meat balls appearance. The folliculitis shows the yeast forms in the hair follicle. There is often an accompanying folliculitis with foreign body giant cell reaction.

OUTLINE

Epidemiology
Disease Associations
Pathogenesis
Laboratory/Radiologic/ Other Diagnostic Testing
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Special Stains/ Immunohistochemistry/ Electron Microscopy
Differential Diagnosis
Prognosis
Treatment
Commonly Used Terms
Internet Links

CLINICAL VARIANTS	CHARACTERIZATION
ATROPHIC
Atrophying tinea versicolor: a clinical and histological study of 12 patients. Crowson AN, Magro CM. Central Medical Laboratories, Winnipeg, MB, Canada.	Int J Dermatol. 2003 Dec;42(12):928-32. Abstract quote   BACKGROUND: We describe 12 patients with an atrophying dermatitis in whom the biopsy findings were compatible with tinea versicolor. DESIGN: We encountered 12 skin biopsies from 12 patients in whom a clinically atrophying dermatosis was associated with light microscopic (LM) evidence of atrophy and epidermal colonization by Pityrosporum sp. Formalin-fixed, paraffin-embedded tissue sections were cut at 5 microns and stained with H&E, alcian blue-PAS and PAS-diastase preparations. RESULTS: Five men and seven women aged 17-73 years in whom lesions characterized as atrophic plaques, patches or macules prompted clinical differential diagnoses including parapsoriasis or mycosis fungoides (MF), anetoderma, lupus erythematosus, and steroid atrophy. A LM examination showed epidermal colonization with pityrosporum hyphae and spores accompanied by variable epidermal and dermal atrophy characterized by rete-ridge effacement, subepidermal fibroplasia, pigment incontinence and elastolysis. CONCLUSIONS: Atrophying cutaneous lesions comprise part of the clinical spectrum of tinea versicolor for which we propose the term 'atrophying tinea versicolor'. The pathogenetic basis is unclear but could be the sequela of delayed type hypersensitivity and the release by T-helper lymphocytes of leukotrienes which perturb collagen metabolism and/or keratinocyte growth. Lesions may be mistaken clinically for MF or other atrophying dermatoses.

PROGNOSIS AND TREATMENT

CHARACTERIZATION

Efficacy of Itraconazole in the Prophylactic Treatment of Pityriasis (Tinea) Versicolor Jan Faergemann, MD, PhD; A. K. Gupta, MD, FRCPC; A. Al Mofadi, MD, FRCPC; A. Abanami, MD, FRCP(Edin); A. Abu Shareaah, MD; Greet Marynissen, PhD

Arch Dermatol. 2002;138:69-73 Abstract quote Background Pityriasis (tinea) versicolor has a high tendency to recur after being treated successfully. Prophylactic treatment to reduce recurrence is needed. Objective To determine whether recurrence of pityriasis versicolor could be prevented by prophylactic itraconazole treatment. Design Open treatment followed by a randomized, double-blind, placebo-controlled phase. Setting Multinational outpatient centers. Patients A total of 239 consecutive patients were included; 238 started open treatment. A total of 209 patients started prophylactic treatment: 106 in the itraconazole group and 103 in the placebo group. Interventions Open treatment: itraconazole, 200 mg once daily for 7 days. Prophylactic treatment: itraconazole, 200 mg, or placebo twice daily 1 day per month for 6 consecutive months. Main Outcome Measures Mycological cure rates at the end of open treatment and at the end of prophylactic treatment. Results Mycological cure at the end of open treatment was 92% (205/223). At the prophylactic treatment end point (6 months), mycological cure was 88% (90/102) in the itraconazole group and 57% (56/99) in the placebo group (P<.001). In open treatment, 11 patients were not able to be evaluated for efficacy. In prophylactic treatment, 4 patients in the itraconazole group and 4 in the placebo group were not able to be evaluated. Adverse events were reported during open treatment by 26 patients (11%) and during prophylactic treatment by 17 (16%) in the itraconazole group and 14 (14%) in the placebo group. No patients experienced any serious adverse events. Conclusions Prophylactic itraconazole treatment is efficacious for pityriasis versicolor after 6 months, as is itraconazole in the treatment of pityriasis versicolor.

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Last Updated June 9, 2005

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