What is Tinea Versicolor
Tinea versicolor (also called pityriasis versicolor) is a common superficial fungal infection of the skin caused by Malassezia species—particularly M. globosa, M. furfur, and M. sympodialis—that manifests as scaly hypopigmented or hyperpigmented macules/patches, primarily on the upper trunk, neck, and upper arms. 1
Pathophysiology
- The causative organism is Malassezia, a lipophilic yeast that is part of normal skin flora 1, 2
- The infection occurs when Malassezia changes from its blastospore (yeast) form to its mycelial (hyphal) form under certain predisposing conditions 3
- Under microscopy, the organism appears dimorphic, showing both short, stubby hyphae intermixed with clusters of spores (the classic "spaghetti and meatballs" appearance) 1, 4
Predisposing Factors
- Exogenous factors: High temperatures and high relative humidity (explaining higher prevalence in tropical climates) 3
- Endogenous factors: Greasy skin, hyperhidrosis, hereditary predisposition, corticosteroid treatment, and immunodeficiency 3
Clinical Presentation
- Characterized by asymptomatic scaly macules or patches that can be hypopigmented, hyperpigmented, or both 1, 4
- Lesions are predominantly located on the upper trunk, neck, and upper arms 1
- In dark-skinned individuals, hypopigmented lesions are more commonly observed, and histologically these lesions show a thicker stratum corneum, more tonofilaments in the granulosum, and more sequestered melanosomes 4
Diagnosis
- Diagnosis is usually clinical, based on characteristic appearance and distribution 1
- When confirmation is needed, potassium hydroxide (KOH) preparation reveals numerous short, stubby hyphae intermixed with clusters of spores 1
Differential Diagnosis
Key conditions to distinguish from tinea versicolor include:
- Confluent and reticulated papillomatosis 4
- Seborrheic dermatitis 4
- Pityriasis rosea 4
- Pityriasis alba 4
- Vitiligo 4
- In some cases, dandruff or mild tinea capitis may present with similar scaling patterns, though these affect the scalp rather than the trunk 5
Clinical Significance
- This is one of the most common superficial fungal infections worldwide, particularly in tropical climates 2
- The condition is chronically recurring with high relapse rates due to Malassezia being part of normal skin flora 1, 2
- Recurrence is common even after successful treatment, necessitating consideration of prophylactic therapy in patients with frequent recurrences 1, 2