Pityriasis versicolor: Etiology, clinical manifestations, and evidence-based management

Chronic superficial, erythro-squamous, common, not very contagious mycosis, due to a lipophilic yeast: Malassezia furfur. In cases of immunodepression, the pathology is frequently encountered and may present non-typical aspects (important role of the laboratory)

Clinical:

Appearance of small spots converging into scaly patches with irregular contours. The lesions are located on the chest, upper limbs, and neck. They are often achromic and fluoresce under Wood's light. On dark skin, clearly follicular forms are often observed, and the neck and face are frequently affected. Be careful, as this pattern can mimic seborrheic dermatitis.

This mycosis is, however, quite characteristic, and clinical diagnosis is generally sufficient.

Sampling:

Take a mycological sample. Scraping with a curette or fingernail easily removes fine scales in one piece, without bleeding. This is the chip sign (very characteristic).

Laboratory diagnosis:

Look for mycelial elements: clear the sample with potassium hydroxide and stain with lactophenol blue. The following are observed:

- short, straight or flexuous mycelial filaments

- clumps of round, thick-walled spores.

Malassezia furfur, PAS stain

Treatment:

For small lesions, conazoles are used, for example, 2% miconazole for one month. For extensive forms, selenium disulfide is preferred.

In addition, change your clothes and iron all linens and sheets with a very hot iron. Subsequent repigmentation of the skin is slow.