What is Pityriasis Alba?
Pityriasis alba is a common, harmless skin issue mostly affecting children and teenagers (refer to the image titled “Pityriasis Alba”). The name “pityriasis alba” actually describes what it looks like, with “pityriasis” referring to the tiny scales, and “alba” meaning the light color (or less color). This skin condition is often thought of as a lesser form of atopic dermatitis, which is a type of skin inflammation, and is usually connected to a history of skin allergies in most people. The main features of pityriasis alba are poorly defined patches and spots (sometimes thin plaques), which are generally round or oval, often with a bit of scaling and occasional itching (refer to the image titled “Macules or Patches Observed in Pityriasis Alba”).
These skin patches are often found on the face, particularly the cheeks, arms, and upper body, and are more noticeable in people with darker skin. At first, the patches might be a little red, but they slowly lighten over time. Sun exposure can make these patches more noticeable, which can lead to people worrying about how they look. However, pityriasis alba tends to go away on its own over time, eventually returning the skin to its normal color. The time it takes for pityriasis alba to disappear can range from a few months to a few years, though most cases typically clear up within a year. The main treatment for this condition involves comfort and understanding, mild steroid creams used on the skin, and gentle moisturizers.
What Causes Pityriasis Alba?
The exact reason why some people get pityriasis alba, a skin condition, is not known. It’s important to know that it isn’t contagious and it’s not caused by any known infection. The condition often appears in people with other allergy-related conditions (a history of atopy), but it can also show up in people who don’t have these conditions. In many cases, it’s thought to be a minor symptom of a skin condition called atopic dermatitis, which is a type of skin inflammation (redness and swelling).
If we were to compare it, it’s quite similar to a skin disorder that leaves color changes on the skin after inflammation has healed (nonspecific dermatitis with residual post-inflammatory hyperpigmentation).
When doctors examine the skin under a microscope they often find less melanin (the pigment that gives our skin its color) being produced in the affected areas. Some studies have also found smaller sebaceous glands (the glands that produce the oil in our skin), signs of anemia due to iron deficiency, and lower levels of copper in the blood sample. There are suggestions that the discoloration might be related to substances like pityriacitrin, produced by Malassezia yeasts (a type of fungi) which filter sunlight. However, these findings aren’t proven and their link to pityriasis alba is still not certain.
Risk Factors and Frequency for Pityriasis Alba
Pityriasis alba is a skin condition that mainly affects children between the ages of 3 and 16. It’s most common in those under 12, with about 5% of kids in the U.S. experiencing it. However, it’s even more prevalent in Egypt and Mali, affecting 18% and 20% of children respectively. While it’s more likely to be found in those with a history of atopy, and slightly more common in boys than in girls, it doesn’t show clear links to any particular race. That being said, the condition is more visible in those with darker skin tones.
This skin condition doesn’t change with the seasons, but its symptoms can worsen or become more visible depending on environmental factors. For example, during the winter, the dry air often found in homes might increase scaling. Then in the spring and summer, spending time in the sun can darken the skin around the lesions and make them stand out more. However, skin color usually returns to normal on its own — typically within a year.
- Most common in kids aged 3 to 16, particularly those under 12
- Affects about 5% of kids in the U.S., but up to 20% in certain other countries
- More likely in those with a history of atopy
- Slightly more common in boys
- Can be more visible in those with darker skin tones
- Symptoms can worsen or be more noticeable because of environmental factors, like dry air or sun exposure
- Skin color usually returns to normal within about a year
Signs and Symptoms of Pityriasis Alba
Pityriasis alba is a skin condition often presenting as painless or slightly itchy light-colored patches, most commonly found on the face. These patches become more noticeable after sun exposure when the surrounding skin darkens. While these spots are usually found during a regular medical check-up, sometimes, they are spotted when either the patient or their parents become concerned about their appearance.
During a physical examination, doctors typically observe several round or oval-shaped light-colored spots. These spots can be different sizes, ranging from as small as 0.5 cm to as large as 5 cm. They are often found on the face, neck, upper arms, or upper chest. The number of spots can vary, with individuals typically having between 4 to 20.
It’s important for doctors to examine these spots carefully since they can look similar to other skin conditions like psoriasis or eczema. Some patients might have used strong creams or lotions that can cause changes in skin color, which complicates diagnosis. Also, doctors look for signs of other skin conditions, like dry skin around the eyes, mouth, ears, or in skin folds.
The condition can have different variations, including:
- “Pigmenting pityriasis,” which features spots with a dark center, surrounded by a lighter, scaly area. This type is more common in people with darker skin from the Middle East and South Africa and is often related to a fungal infection.
- “Extensive pityriasis alba,” which is characterized by widespread and symmetrical spots. Compared to standard pityriasis alba, these spots tend to be less scaly, stay longer, are not associated with any symptoms, and are more commonly found on the trunk than the face. Their unique feature is that they do not show spongiosis, a particular sign of inflammation under the microscope.
Testing for Pityriasis Alba
Pityriasis alba, a skin condition typically seen in children or adolescents, is usually easy to diagnose based on the appearance and distribution of skin lesions. However, there are multiple tests for those times when the diagnosis isn’t clear-cut.
One of these tests involves using a Wood’s lamp, which is a special light that can make certain skin conditions more visible. When pityriasis alba skin lesions are examined under this light, they might look more prominent but won’t glow or fluoresce. This is different from another skin condition called vitiligo, where the affected skin areas appear brighter under the Wood’s lamp and their edges are more sharply defined.
Another test is the potassium hydroxide preparation of skin scraping. This test allows doctors to look for fungal elements that would indicate conditions such as tinea versicolor or tinea corporis. In pityriasis alba, this result is typically negative, which means no fungal elements are found.
Most of the time, a skin biopsy isn’t necessary. However, if one is performed, it can help tell the difference between pityriasis alba and a condition called mycosis fungoides.
There’s another technique called dermoscopy, which allows doctors to examine the skin in detail. In cases of pityriasis alba, it shows dull white areas with loosely defined edges (due to the loss of melanin pigments in the lower layer of the skin) and white scaling that usually forms a pattern or stays concentrated within the creased areas of the skin. In darker skin types, a faint light-brown pigment pattern is also noted in the background. A distinctive feature is “perieccrine semicircles,” a specific type of skin discoloration seen around sweat glands. These appear largely in darker skin types and indicate decreased pigmentation ability in the associated area. You might also see small white areas and brown dots in individuals with darker skin.
Treatment Options for Pityriasis Alba
Pityriasis alba is a harmless and temporary skin condition that usually gets better on its own. However, it might take various periods from several months to a couple of years before it completely disappears, with most cases disappearing within a year.
There are several ways to manage pityriasis alba, each plan is tailored to help specific symptoms and help the skin regain its normal color.
Protecting your skin from the sun is crucial. When the skin around the affected areas darkens due to sun exposure, the contrast can make the condition look worse. Using sunscreen can help prevent this contrast from developing.
Applying creams or ointments known as low-potency topical steroids, such as 1% hydrocortisone, may help ease redness, itching and promote re-coloring of the skin more quickly.
Mild skin moisturizers like petroleum jelly and creams can help reduce flaky skin or scaling.
Topical calcineurin inhibitors, such as 0.1% tacrolimus ointment and 1% pimecrolimus cream, can effectively treat pityriasis alba. Although these are not frequently used due to their high cost.
Calcitriol, a type of topical vitamin D, may also be used, which are as effective as tacrolimus.
Other treatments for more extensive cases include psoralen plus ultraviolet-A (PUVA) photochemotherapy, which is a type of light therapy, and targeted phototherapy with a 308-nm excimer laser, a form of laser treatment that targets specific areas of the skin.
What else can Pityriasis Alba be?
Before diagnosing a skin condition as pityriasis alba, it’s important to check for other skin conditions that have similar symptoms. Here are some of these potential conditions and their distinctive features:
- Nevus depigmentosus: This condition typically appears on the trunk in a scattered pattern, and the marks don’t grow bigger or multiply.
- Psoriasis: Early red marks might look like pityriasis alba, but the absence of such marks on elbows, knees, and scalp, as well as the lack of salmon-colored scales, rule out this condition.
- Tinea versicolor: If you test positive for the hyphal and yeast forms of Malassezia furfur upon performing a potassium hydroxide examination, you might be suffering from this condition.
- Vitiligo: This skin condition is identified by a complete loss of color, especially around the eyes and mouth.
- Mycosis fungoides: Persistent and changing spots that are also uncomfortable could indicate this disease.
- Pityriasis lichenoides chronica: This condition leads to wide-ranging spots on the trunk and limbs. After the disease disappears, it leaves behind pale skin, similar to pityriasis alba.
- Delusional tinea: This illness might cause chronic changes in skin color, resembling pityriasis alba.
- Leprosy: Certain areas where people come into contact with armadillos might see a prevalence of this disease.
- Nummular eczema: Unlike pityriasis alba, this condition causes intense itchiness.
There are also other conditions that could be confused with pityriasis alba due to similar features. These include skin color changes due to inflammation or certain medications, spots related to tuberous sclerosis, conditions such as pityriasis rosea, seborrhea, atopic dermatitis, contact dermatitis, and diseases like nevus anemicus, discoid eczema, and tinea corporis. Always consult with your healthcare provider for a precise diagnosis.
What to expect with Pityriasis Alba
Pityriasis alba is a skin condition that gets better on its own. Most people with this condition will find that their skin color returns to normal over time. A large part of the worry for those with this condition has to do with appearance; that’s often why they look for medical help. Also, areas of skin with less pigment – or color – are more likely to get sunburned, so it’s important to take steps to protect them.
How long this skin condition lasts varies. It could go away in just a few days or it could stick around for a few years. In some cases, treatment can help clear it up faster.
