Pityriasis alba is a dermatosis, a common skin disease, most common among patients aged 3 to 16 years.
The cause is not entirely clear, but a number of factors are attributed to it, including:
- Prolonged exposure to the sun
- Dark skin
- Atopic dermatitis
On physical examination, multiple hypochromic (whitish) patches are found, which may be round or oval, with diffuse margins, single or multiple, and accompanied by fine desquamation.
They usually affect the face, neck, forearms and upper chest.
As previously mentioned, the reason why it occurs has been little studied, but ultraviolet radiation has been found to be a triggering factor, which causes an inflammatory reaction in the skin leading to malfunction of melanocytes (cells that produce skin colour). In fact, a loss of the number, morphology and distribution of active melanocytes has been described.
How can we treat it?
One of the main goals of treatment is education to limit exposure to triggers, such as exposure to sunlight, and to apply sunscreen daily every three to four hours.
- Mild emollients (substance used as a medicine to soften a hardness, tumour or inflammation), such as petroleum jelly and moisturisers, reduce scaling and restore the skin barrier.
- Treatment with topical calcineurin inhibitors, are highly effective
- Low potency topical steroids, such as cream or ointment, can reduce the erythema and tingling typical of irritation, and accelerate repigmentation. But these should be used with caution.
- For extensive cases, targeted phototherapy with an excimer laser is included.
This skin disorder often generates great cosmetic concern on the part of the patient or their parents, as it also becomes more aesthetically noticeable during spring and summer.
It should be borne in mind that this dermatosis is not a fungus, it is not contagious. It is only an inflammation of the skin, and the time it takes to resolve it varies and can last for months, although most heal in less than a year.
