By Dr Dana Fara’neh–Batayneh, Dermatologist
A common skin condition seen mainly in children and adolescents during summer, Pityriasis Alba (abbreviated P. Alba) can be worrying to parents who sometimes confuse it with other skin diseases.
White spots on the skin with fine scales (hence the name Pityriasis Alba: Pityriasis which in Latin means scaly and Alba means white). They usually start with a mild pink to red colour before turning to white. They are usually half to three centimetres in size (although sometimes larger), affect children and adolescents most frequently, and present on the face (especially the cheeks), the neck, the shoulders and arms. The patches are usually asymptomatic, although some patients complain of itching.
The exact cause of P. Alba is unknown. It may be a result of a defect in transferring melanin (the pigment that gives skin its colour) to the skin surface, giving the spots their white colour. It occurs more commonly in people who have dry skin or eczema, and is much more common in people with darker skin tones or after sun exposure and tanning. This is because the surrounding skin is dark in these cases, making the patches look more prominent, and therefore causing patients to seek medical advice.
Diagnosis can be made by simple observation without a need for investigation. But we have to distinguish this from Vitiligo (a disease that causes the loss of skin colour in blotches) by using the Wood’s Lamp. Under this lamp, P. Alba is hypopigmented, whereas vitiligo looks milky white or depigmented. Another skin disease that can look similar to P. Alba is Tinea Versicolor, which is a fungal skin infection that can be treated with antifungal drugs.
We usually reassure parents that this is a self-limiting skin condition that usually resolves spontaneously without treatment. But in some cases, the patches persist for months or years before eventually clearing up.
- Hydration and sun avoidance are key factors in prevention and treatment
- A mild cortisol cream can be used on the spots to help treat the inflammation
- Calcineurin Inhibitors (like Tacrolimus and Pimecrolimus) can be used as well
- Ultraviolet therapy may be beneficial in severe or extended cases
Prevention is always key!
To avoid getting P. Alba, limit sun exposure, wear sunscreen with adequate SPF (preferably 50) when spending long hours in the sun and frequently hydrate your skin with a moisturizer, especially during summer and in people who have eczema or dry skin