Pityriasis Alba (Milk Patches): Causes, Why It Is Not a Fungal Infection, and How to Treat It
Many parents bring their child to the doctor worried: "Why does my child have faint white patches on the cheeks? Is it vitiligo?" In fact, faint, scaly white patches on a child's face are most often pityriasis alba, a very common condition that is harmless, and skin colour usually returns to normal on its own.
What confuses many people, and leads them to the wrong treatment, is the name. In Thai, both "klak" and "kluen" are names of fungal diseases, so many people buy antifungal cream and still the white patches never go away. In this article, a dermatologist explains what pityriasis alba is, why it is not a fungal infection, how to tell it apart from vitiligo and other look-alike conditions, and the evidence-based approach to treatment.
What Is Pityriasis Alba?
Pityriasis alba, known in Thai as "klak nam nom" or "kluen nam nom", is a mild inflammatory skin rash that causes patches lighter than the normal skin (hypopigmented), with fine scale and poorly defined edges. It usually appears on the face, especially the cheeks, and is most common in children and teenagers.
Key points to understand from the start:
It is not a fungal infection, unlike true ringworm and tinea versicolor, which are caused by fungi.
It is not contagious. It does not spread from person to person, or through touch or sharing belongings.
The skin is lighter, not completely white. Pigment production in the area is temporarily reduced, not permanently lost as in vitiligo.
It can clear on its own. Skin colour gradually returns to normal over time.
Pityriasis alba belongs to the same family of conditions as atopic dermatitis (eczema). It is often seen in people with easily dried-out skin or a tendency toward eczema, and it is a low-grade inflammation that temporarily disrupts pigment production.
Why Does the Name Include "Klak" and "Kluen" If It Is Not a Fungus?
This is where many people in Thailand end up on the wrong treatment. The Thai names are descriptive, based on how the patches look (pale, scaly patches resembling the colour of milk). They do not mean the condition is caused by the ringworm or tinea versicolor fungus.
What happens when this is misunderstood:
Antifungal cream is applied and the white patches do not go away, because there was never a fungus to kill.
Some people use antifungal products for a long time, or use combination creams or strong steroid creams on their own without need, which can cause side effects on delicate skin such as the face.
Time and peace of mind are wasted for nothing.
In short: if the white patches really are pityriasis alba, antifungal medicine will not help. What actually helps is moisturising and reducing inflammation, as described in the treatment section.
What Causes Pityriasis Alba?
The exact cause is not fully known, but dermatologists believe several factors contribute together:
Dry skin and a tendency toward eczema (atopy): children with easily dried-out skin or atopic dermatitis are more likely to develop pityriasis alba.
Low-grade skin inflammation: this temporarily reduces the amount of pigment that pigment-producing cells (melanocytes) deliver to the upper layers of the skin, so the area looks lighter than the surrounding skin.
Sunlight: it is not a "cause" of the condition, but it makes the patches more visible (explained below).
Why Is Pityriasis Alba More Noticeable in Summer or After Sun Exposure?
Many people notice that the white patches stand out more in hot weather or after time in the sun, and mistakenly think the condition has flared up. In fact:
The normal skin around the patches tans in the sun.
The pityriasis alba patches, where pigment cells are less active, do not tan along with it.
The difference in colour becomes more obvious, so it looks worse even though the condition itself is unchanged.
This is why sun protection is an important part of care: it helps reduce the colour difference.
What Are the Symptoms of Pityriasis Alba and How Can You Recognise It?
Typical features that suggest pityriasis alba:
Patches lighter than normal skin, round or oval, about 0.5 to 3 centimetres in size.
Poorly defined edges that blend gradually into the surrounding skin (not sharp edges as in vitiligo).
Fine scale, especially in the early stage.
Location: most often on the cheeks and face, less often on the upper arms, neck and shoulders.
Usually not itchy, or only mildly itchy.
Most common in children and teenagers aged about 3 to 16 years, and more noticeable in people with darker skin.
White Patches on the Skin: Is It Pityriasis Alba? How to Tell It Apart From 5 Look-Alike Conditions
"White patches" on the skin have more than one cause. Telling them apart correctly matters, because some conditions need completely different treatment, and some are signs of a disease that needs prompt care.
Basic ways to tell the different white patches apart:
Pityriasis alba: lighter than the skin, blurry edges, fine scale, usually on the cheeks, face and upper arms, seen in children and teenagers. Not a fungus, and it clears on its own.
Tinea versicolor (Pityriasis versicolor): patches that are lighter or darker, appearing as spots, with scale that flakes off when lightly scraped, usually on the trunk, back, chest and neck. It is a fungal infection, fungus is found on a KOH test, and it improves with antifungal treatment.
Vitiligo: patches that are chalk-white with sharp edges and no scale, usually around the eyes, mouth, hands, feet and skin folds. Pigment is permanently lost, hair in the patch may turn white, and under a Wood's lamp the patch glows brightly.
Post-inflammatory hypopigmentation: lighter skin following the shape of a previous rash or wound, with a history of a rash, acne or injury in that exact spot.
Leprosy: pale patches that are numb, with reduced feeling to touch and no sweating in the patch. Although uncommon, it must not be missed, so see a doctor promptly.
What worries parents most is the fear of vitiligo. Differences that help tell them apart at first:
Pityriasis alba: "faintly" white, blurry edges, scaly, with some pigment still visible.
Vitiligo: "completely" white like chalk or milk, with sharp edges and no scale, and under a Wood's lamp the patch glows brightly.
However, telling them apart by eye is sometimes not easy, especially in the early stage. A dermatologist can confirm the diagnosis with a Wood's lamp, a fungal scraping (KOH), or, in unclear cases, a skin biopsy.
Is Pityriasis Alba Dangerous? Does It Clear on Its Own?
It is not dangerous. Pityriasis alba is not a serious condition. It does not spread to internal organs, does not turn into cancer, and is not contagious. The main effect is cosmetic and the worry it causes.
It can clear on its own. Skin colour usually returns to normal gradually, but this takes months to years, and in most children it improves clearly by adulthood. Patience and regular skin care matter more than rushing treatment, because there is no medicine that "speeds up" the return of colour.
Evidence-Based Treatment for Pityriasis Alba
The goals of treatment are to reduce inflammation, increase moisture and reduce the colour difference while pigment recovers, in the following order:
Moisturiser (the core of treatment): applying moisturiser regularly every day helps reduce scale and inflammation. It is the most effective and safest measure.
Sunscreen: use sunscreen or avoid strong sun to reduce tanning of the surrounding skin, so the white patches blend in better.
Mild steroid cream, short term: for example low-strength hydrocortisone, used only while there is inflammation or itching, under a doctor's guidance. It should not be applied on the face continuously by yourself.
Calcineurin inhibitors: such as tacrolimus or pimecrolimus, a good option for the face because they do not thin the skin the way steroids can. Suitable for children under a doctor's supervision.
Care for the underlying eczema or dry skin: because pityriasis alba often occurs together with dry skin or atopic dermatitis.
What not to do:
Do not buy antifungal cream to apply on your own, because it is not a fungus.
Do not continuously apply combination creams or strong steroids on a child's face by yourself.
Do not scrub hard, because it only irritates the skin further.
Signs You Should See a Dermatologist
Although most pityriasis alba is not dangerous, see a dermatologist if:
The patches are completely white with sharp edges or are spreading quickly, since vitiligo needs to be ruled out.
The patch is numb, with reduced feeling to touch or a pinprick, since leprosy needs to be ruled out.
There are many patches spread over the body or a large affected area.
An adult has new white patches and has never had them before.
The patches have not improved after several months of skin care and initial treatment.
Seeing a dermatologist allows an accurate diagnosis with specialised tools (Wood's lamp, fungal testing) and a care plan suited to each person's skin, especially to separate pityriasis alba from vitiligo and leprosy, which need very different care.
Frequently Asked Questions About Pityriasis Alba (Milk Patches)
Are "klak nam nom" and "kluen nam nom" different?
No. They are two names for the same condition (pityriasis alba), which people in Thailand use interchangeably. Some say "klak nam nom", others say "kluen nam nom" or "kluen daet". All refer to faint, scaly white patches that are not caused by a fungus.
Is pityriasis alba contagious?
No, because it is not caused by germs. Sharing belongings, touching, hugging or playing with other people is fine.
Will antifungal cream make it go away?
No, because pityriasis alba is not a fungus. What actually helps is moisturiser, sunscreen and anti-inflammatory medicine as advised by a doctor. If white patches never clear despite antifungal cream, suspect that they were not a fungal infection in the first place.
Does pityriasis alba clear on its own, and how long does it take?
It can clear on its own, but it takes months to years. Skin colour gradually returns, and there is no medicine to make it go away quickly. Regular skin care helps the skin look better while you wait.
Is it true that pityriasis alba is caused by a vitamin or calcium deficiency?
This is a misunderstanding. Pityriasis alba is linked to dry skin and a tendency toward eczema rather than to a lack of any particular nutrient. Taking vitamin supplements when you are not actually deficient does not make the white patches clear faster.
Is pityriasis alba in adults dangerous?
Pityriasis alba can occur in adults too and is usually not dangerous. However, an adult with newly appearing white patches needs to be clearly distinguished from vitiligo, tinea versicolor and other conditions, so we recommend seeing a dermatologist to confirm the diagnosis.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed August 25, 2026
This article provides general information and is not a diagnosis or personalised treatment advice. If you have any concerns about white patches on your own or your child's skin, we recommend consulting a dermatologist for an accurate diagnosis.
Consult a dermatologist at Siam Dermatology, a specialist skin clinic
LINE: @siamderm
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