An Overview of Pityriasis Alba

Pityriasis alba is a common, benign (non-cancerous) skin disorder that typically affects children ages 6 to 12. Someone with this condition has raised, rounded patches of lighter skin. These patches are mainly on the face, but they can show up on other parts of the body, too.

The condition is named for its scaly appearance and white patches. The name pityriasis alba comes from the Latin words pityrus, meaning wheat, and alba, for white.

This article describes the condition, its symptoms, causes, diagnosis, and treatment options.

Symptoms

Pityriasis alba causes lightly colored spots to develop on the skin. Most often, they are found on the cheeks. But they can also show up on the neck, chest, back, and upper arms. Symptoms include:

• Pink or red spots that fade to lighter than usual skin
• Affected areas ranging from a quarter of an inch to an inch in size
• Circle or oval shape
• Undefined borders that gradually blend into normally pigmented skin
• Flaky and itchy patches of skin

The patches themselves are often raised and may be scaly. The scaliness is most noticeable during the winter months when the air is drier. During the summer, the spots can be easier to see when the skin around them is tanned.

The lesions aren't painful, but they might be mildly itchy.

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Causes

Although an exact cause is still unknown, pityriasis alba may be related to other skin conditions. For example, it is thought that when a case of dermatitis (skin irritation) heals, it may leave behind a lighter patch of skin.

It may also happen if you use too much topical corticosteroids when treating eczema. This can cause areas of patchy rash to lighten as they heal.

Some genetic disorders are also believed to cause cutaneous hypopigmentation (loss of skin color). This can happen when melanocytes, the cells that produce the skin pigment melanin, have lower activity. Melanin makes the skin darker.

Diagnosis

Usually, your doctor can diagnose pityriasis alba by simply looking at the rash and reviewing your child's symptoms and medical history.

Pityriasis alba is often confused with tinea versicolor, where an overgrowth of fungus on the skin causes patchy white lesions. However, there are several ways a doctor can distinguish between the two disorders:

• A Wood's lamp examination uses a handheld ultraviolet (UV) light to highlight differences in skin color. It is usually used in a dermatologist's office in a darkened room.
• Potassium hydroxide (KOH) can be used to diagnose fungal infections, like tinea versicolor or other fungal conditions such as tinea corporis (ringworm). For this test, the skin is lightly scraped to remove some skin cells, which are mixed with potassium hydroxide and examined under a microscope. This process makes fungus easier to see.

Pityriasis alba can also be confused with vitiligo, an autoimmune disease where pigment is lost in some patches of skin. However, vitiligo has very distinct borders, which will help your doctor distinguish between the two.

Vitiligo patches appear first on sun-exposed parts of the body. It can often occur after a triggering event such as a sunburn. It can then spread to the armpits, eyes, groin, genitals, naval, and rectal areas.

Pityriasis alba also develops in sun-exposed areas. However, it isn't clear if sun exposure triggers the condition.

Treatment

Treatment of pityriasis alba is not always necessary. Most cases usually resolve on their own by adulthood. Still, many parents choose to treat it for cosmetic reasons, especially if their child is self-conscious about their skin.

Even with treatment, recovery can sometimes take several months. Your child should avoid tanning (natural or artificial) and consistently use sunscreen (at least 30 SPF) to speed healing.

Moisturizers

Moisturizers that contain petrolatum, mineral oil, squalane, or dimethicone can help soften the skin and reduce scaliness, especially on the face. Brands that are effective, inexpensive, and easy to find include:

• Aquaphor
• Aveeno Cream
• Eucerin

You may also ask your physician for recommendations. Good skin hygiene, in general, can help the patches heal faster.

Over-the-Counter Hydrocortisone

You can use an over-the-counter (OTC) 1% hydrocortisone cream (topical steroid) sparingly if there is itchiness. However, care should be taken when using hydrocortisone on the face.

Do not apply around the eyes or on the eyelids. Don't use OTC hydrocortisone for more than four weeks continuously unless your doctor advises you to.

Topical Calcineurin Inhibitors

Elidel (pimecrolimus) and Protopic (tacrolimus) are non-steroidal medications that your doctor may prescribe to clear the rash. They aren't often needed but are sometimes suggested in more severe cases.

Topical calcineurin inhibitors are most often used to treat eczema. They are used off-label for pityriasis alba. This means the Food and Drug Administration hasn't approved them specifically for this purpose. Because they are not steroids, you can safely use them around the eyes.

Summary

Pityriasis alba is a condition in which patches of skin lose pigmentation and are lighter in color than surrounding skin. It most often affects elementary-age children. The affected areas of skin are small—usually no bigger than an inch in diameter.

Your doctor can diagnose pityriasis alba based on a physical exam and skin tests. Most often, the condition heals on its own without treatment. But, if your child feels self-conscious, your doctor may advise treating the patches with moisturizers or other topical medications to speed the healing process.

A Word From Verywell

Anytime your child has an unusual rash, you should make an appointment with their pediatrician. Pityriasis alba is a harmless condition, and there is no medical reason to treat it. But if doing so will make your child feel more confident, that's a good enough reason to consider it. Remember that, in most cases, pityriasis alba fades by adulthood.