Pityriasis alba is a skin condition that may lead to patches of skin discoloration. It is typically harmless and not contagious. Pityriasis alba usually improves without treatment within a year.

Although the exact cause of pityriasis alba remains unclear, there are some known risk factors.

In this article, we look at the symptoms and causes of pityriasis alba and the potential treatments.

Pityriasis alba is a common and benign skin condition. It is not contagious, meaning that it does not spread from one person to another.

Pityriasis alba occurs most frequently in children and adolescents aged 3–16 years, with about 90% of cases of pityriasis alba affecting children under the age of 12 years.

Experts estimate that pityriasis alba may affect about 5% of children in the United States.

Pityriasis alba presents as pale or light plaques on the skin. Plaques are areas of textured skin.

Doctors may describe the plaques as hypopigmented, meaning that the affected skin does not have as much melanin as the surrounding skin. Melanin is the natural pigment that determines people’s hair, eye, and skin color.

The hypopigmented plaques, or lesions, tend to develop on the:

  • face, particularly the cheeks
  • arms
  • upper trunk

People may have between four and 20 lesions, which tend to be about 0.5–5 centimeters in diameter.

The light patches are usually more noticeable in people with darker skin tones. In people with lighter skin tones, the patches tend to be more visible when they have a suntan.

In many cases, pityriasis alba starts with discolored, scaly patches, which may be itchy and round or oval-shaped. These then resolve but leave behind hypopigmented patches.

Most of the time, the skin gradually returns to its usual appearance, but this could take several months to years. For most people, the condition improves within 1 year.

It is unclear what causes pityriasis alba. However, according to the American Osteopathic College of Dermatology, pityriasis alba could have a connection with eczema.

Eczema is an umbrella term that describes a group of conditions that cause an itchy, swollen rash on the skin. The various types of eczema include:

More than 31 million people in the U.S. have some form of eczema.

People with atopy have a higher chance of developing pityriasis alba than other people. The American Academy of Allergy, Asthma & Immunology describe atopy as the genetic tendency to develop an allergic disease, such as:

Therefore, pityriasis alba is more likely in people who live with an atopic health condition or have a family history of atopic health conditions.

Pityriasis alba often gets better without treatment, but it may take time.

It may take several months or a few years for normal skin pigmentation to return. However, for most people, the skin recovers within 1 year.

People can take the following steps to relieve the symptoms:

  • Try moisturizing treatments: Mild emollients, such as petroleum jelly and creams, may reduce skin scaling.
  • Discuss the use of topical medications with a doctor: Pimecrolimus (Elidel), tacrolimus (Protopic), and crisaborole (Eucrisa) are nonsteroidal creams that may minimize pityriasis alba-associated itching.
  • Try low potency topical steroids: A 1% hydrocortisone cream or ointment may reduce skin itching and discoloration. It may also help speed up repigmentation.

People who find the appearance of pityriasis alba bothersome may also wish to limit sun exposure or use sunscreen. When the skin around the patches gets darker, it makes the hypopigmented areas more visible.

Pityriasis alba usually improves over time without treatment from a doctor.

A pharmacist may recommend over-the-counter skin treatments to help with symptoms such as itching or discoloration.

A person should see a doctor for advice if their symptoms interfere with everyday life. A doctor may recommend higher dose skin treatments that are available with a prescription. In some cases, they may refer the person to a specialist skin doctor, known as a dermatologist.

Pityriasis alba is a common skin condition that mainly affects children and adolescents.

It causes areas of pale or lighter skin, which tend to resolve without intervention, usually within a year. The condition sometimes starts with small, round patches of scaly skin that may be discolored and itchy before becoming hypopigmented.

Pityriasis alba patches are more noticeable on people with darker skin tones or tanned skin. Due to this, people with pityriasis alba may wish to avoid excessive sun exposure or use sunscreen to protect the skin.

Moisturizing treatments, such as petroleum jelly, can help reduce itching.

A person should speak with a doctor if pityriasis alba symptoms interfere with everyday life. The doctor may prescribe a steroid cream to help ease symptoms.