Chapter 147: Tinea Versicolor

PATIENT STORY

A young black man presents to the office with a 5-year history of white spots on his trunk (Figure 147-1). He denies any symptoms but worries if this could spread to his girlfriend. These spots get worse during the summer months but never go away completely. He was relieved to receive a treatment for his tinea versicolor and to find out that it is not spread to others through contact.

INTRODUCTION

Tinea versicolor is a common superficial skin infection caused by the dimorphic lipophilic yeast in the genus Malassezia, formerly known as Pityrosporum. The most typical presentation is a set of hypopigmented macules and patches with fine scale over the trunk and proximal upper extremities in a capelike distribution.¹

SYNONYMS

Pityriasis (from Pityrosporum) versicolor is actually a more accurate name, as "tinea" implies a dermatophyte infection. Tinea versicolor is caused by yeast in the genus Malassezia and not a dermatophyte.^1,2

EPIDEMIOLOGY

• Seen more commonly in men than in women.

• Seen more commonly in adolescents and young adults.

• Seen more often during the summer and is especially common in warm and humid climates.

ETIOLOGY AND PATHOPHYSIOLOGY

• Tinea versicolor is caused by yeast in the genus Malassezia which is a lipid-dependent, dimorphic fungus that is a component of normal human cutaneous flora.^2,3

• Malassezia lipophilic yeasts are causative agents in tinea versicolor, seborrheic dermatitis, and Malassezia folliculitis and can even exacerbate atopic dermatitis.² In one microbiology study using polymerase chain reaction (PCR), the authors were able to determine the prevalence of various Malassezia species on patients with Malassezia associated skin conditions.² The two most common species isolated from humans were M. globosa and M. furfur.²

• Transformation of Malassezia from yeast to the pathogenic mycelial form followed by invasion into the stratum corneum precedes the development of the classic appearance of tinea versicolor.⁴

• Versicolor refers to the variable changes in pigmentation noted in this condition.^2-4

• Hypopigmentation changes are secondary to melanocytic damage caused by azelaic acid produced by the genus Malassezia, while the hyperpigmented and erythematous lesions are a result of an inflammatory reaction to the organism.⁴

• Malassezia is lipid dependent and thrives on sebum and moisture. The lesions are more common in areas of greater sebum production, such as the upper trunk and proximal upper extremities.^2,3

DIAGNOSIS

CLINICAL FEATURES

Tinea versicolor consists of hypopigmented, hyperpigmented, or pink macules ...