Pityriasis Versicolor

ICD-11

1F2D.0

Synonyms

Tinea versicolor.

Epidemiology

Most common in young adults during spring and summer seasons.

Definition

Superficial cutaneous mycosis caused by lipophilic Malassezia yeasts (primarily M. globosa) with hypo- and hyperpigmented macules.

Aetiology & Pathogenesis

Causative lipophilic Malassezia yeasts belong to the resident flora of human skin. Various predisposing factors trigger hyphal growth stage.

Predisposing factors: sweating, humid climate, immunosuppression.

Signs & Symptoms

Variable picture; several clinical types:

Hyperpigmented type: small, yellow-brown macules, disseminated, fine scale, sometimes modest pruritus.
Depigmented type (pityriasis versicolor alba): small white macules in dark-skinned or tanned individuals.
Erythematous type: erythematous macules with infiltrate and only minimal scale.
Follicular type: acneiform, often at the back.
Atypical forms: solitary or few lesions, often in atypical sites.

Localisation

Upper trunk, less often lower trunk and proximal extremities.

Classification

Non applicable.

Laboratory & other workups

KOH examination or stripping with cellophane tape; methylene stain for grouped spores and hyphae on scales under microscope (spaghetti and meatballs pattern).

Dermatopathology

Hyphae and spores in the stratum corneum and in the acroinfundibula.

Course

Usually persistent or recurrent, sometimes clears spontaneously.

Complications

None.

Diagnosis

Clinical features, microscopic examination of scales, yellow-orange fluorescence under Wood’s light (365 nm).

Differential diagnosis

Guttate hypomelanosis, vitiligo, pityriasis alba, pityriasis rosea, tinea corporis, seborrheic dermatitis, erythrasma.

Prevention & Therapy

Prevention: careful drying of skin after shower, wearing breathable fabrics to decrease sweating, avoidance of tight clothing, avoidance of highly moisturizing skin products. Treatment of scalp reservoir.

Topical treatment of the entire body (shampoos containing imidazoles, selenium sulfide, ciclopirox or zinc pyrithione); in cases with frequent recurrences or widespread involvement: systemic anti-fungals such as itraconazole.

Special