Pityriasis versicolor

The tinea versicolor , also known incorrectly as tinea versicolor, is a skin infection caused by a fungus that normally lives on the skin. When this fungus becomes a pathogen, it invades the most superficial layers of the epidermis without producing inflammatory or immunological pathological alterations.

Causes of pityriasis versicolor

It is produced by a fungus called Malassezia Furfur, which is the pathogenic form of a yeast that is usually found on the skin called Pityrosporum ovale. This fungus lives in the seborrheic areas of the skin, which makes it exceptional before puberty (since at this stage there is no sebaceous secretion).

The existence of areas of the skin with sebaceous secretion favors the development of the fungus, which passes from its saprophytic (yeast) to the pathogenic (mycelial) form. Local factors such as humidity, hyperhidrosis, seborrhea, use of topical corticosteroids and fatty creams contribute to this phenomenon; and general factors such as diabetes , treatment with corticosteroids, antibiotics or immunosuppressants.

Its highest incidence is in summer and spring. It affects young adults and is rare in children.

Symptoms of pityriasis versicolor

It is characterized by the presence of spots on the skin, sometimes brown and sometimes achromic (the normal coloration of the skin is lacking), with well-defined borders, which can be isolated or confluent and give the skin a map-like appearance. These spots have a fine peeling that can be demonstrated by scratching with the nail. They are located mainly on the trunk and neck. Occasionally they itch.

How is it diagnosed?

The diagnosis is made by the clinic, which is typical, and by the sign of the nail, which is that when scraping with the nail on spots the skin peels off.

In case of doubt, two other techniques can be used:

• Illumination of the lesions with Wood’s light demonstrating a pinkish fluorescence of the lesions.
• Perform a direct examination of skin scales obtained with cellophane and stained with fountain pen ink. If they are pathogenic, the presence of pathogenic forms will be observed.

The cultures are of little diagnostic value, since they are constituents of the normal flora of the skin.

It is important to differentiate it from other diseases such as vitiligo , pityriasis rosea or seborrheic dermitis with trunk involvement.

Treatment of pityriasis versicolor

Because it is not a contagious process, it is unnecessary to take measures to prevent its possible contagion to other people.

Current therapeutic measures are very useful, being preferable the use of local treatments, which should be applied throughout the trunk and upper extremities for 10-15 days followed by a week of rest and repeating again.

These local treatments are:

Keratolytics and antiseborrheic, to prevent the fungus from developing further.

The most used are:

• 20% Sodium Hyposulfite – 50% Propylene Glycol.
• Selenium sulfide.

Antifungals: Imidazole derivatives; terbinafine; griseofulvin; cyclopyroxolamine.

In addition, oral antifungal agents can be used in situations in which local treatment is insufficient or because the patient requests it to find it more comfortable. The two most used are ketoconazole and itraconazole; the latter preferably because it has fewer side effects.

Despite the healing, patients must be warned that after the process there will be achromic stains, without nail sign, which are considered residual elements that will disappear spontaneously.

You should go to the doctor before the appearance of spots, brown or whitish, with peeling of the skin when scraping with the nail, especially if you have already had an episode.