Pityriasis alba is a common skin disorder in children. The exact cause is unknown. However, it is thought that the condition may be associated with eczema, a common skin disorder that causes scaly, itchy rashes.
People with pityriasis alba develop red, flaky patches on their skin that are round or oval in shape. The patches will usually clear up with moisturizing creams or may go away on their own, but often leave pale marks once the redness has faded.
The exact cause of pityriasis alba is not known. According to a 2009 review published in Pediatric Health, pityriasis alba is commonly considered a mild form of atopic dermatitis or eczema (Guareschi, et al., 2009).
Eczema is caused by a reaction of your body’s immune system. It is similar to an allergic reaction. However, eczema is not caused by allergies. Most people outgrow eczema and pityriasis alba by early adulthood.
Pityriasis alba is most common in children and adolescents. It is estimated to occur in 2 to 5 percent of children and is most frequently seen in children between 6 and 12 years old. The disorder is found all over the world, but may be more common in developing countries (Guareschi, et al., 2009).
Pityriasis alba often appears after a child is exposed to the sun without sunscreen protection or in children who take frequent hot baths. However, it is unclear if these factors cause the disease. Children with dark skin are at a higher risk of having the skin disorder. It is also more noticeable in children with dark skin.
Pityriasis alba is not contagious.
People with pityriasis alba experience round or oval patches of pale pink or red skin. The patches may appear on the following parts of the body: face (most common), upper arms, neck, and upper middle of the body.
The pale pink spots may fade into a white patch after several weeks. Patches usually clear up within a few months, but in some cases can last for several years. They are more noticeable in the summer months when the surrounding skin becomes tan. The patches will not become tan after sun exposure, but wearing sunscreen may make patches less noticeable in the summer months.
People with this condition may also experience flaky skin (sometimes described as “scales”).
No treatment is required and the patches will eventually go away. A doctor may prescribe a moisturizing cream or topical steroid cream such as hydrocortisone to help reduce skin discoloration or to help with any dryness or itchiness.
The patches will typically clear up on their own or with treatment creams. However, the patches can return and the child may need to use the creams again. Most cases resolve for good by adulthood.