Pityriasis Alba: Symptoms, Causes & Treatment

Pityriasis alba is a harmless skin condition that causes pink or reddish patches that fade over time, leaving lighter areas on the skin. It is most common in children and young adults, but it can occur at any age.

The exact cause of pityriasis alba is not known, but it is not hereditary. This means that even if someone in the family has it, it does not increase the risk for other relatives.

Treatment for pityriasis alba is managed by a dermatologist and is not always necessary, since the spots often disappear naturally within a few months. However, when the spots are widespread or take longer to fade, the doctor may recommend corticosteroid ointments or immunosuppressive creams.

Common symptoms

The main symptoms of pityriasis alba include:

• Round or oval reddish patches that fade within a few weeks;

• Lighter spots on the skin;

• Small, thin, light-colored plaques or blisters;

• Mild flaking of the skin;

• Mild itching or pruritis.

These patches usually measure between 0.5 and 5 cm in diameter and may appear in multiples, typically between 4 and 20 spots. They most often develop on the face, neck, arms, or chest, but can also appear on the back or shoulders. The lighter patches are usually more noticeable in the summer when surrounding skin becomes tanned, making the contrast more visible.

Confirming a diagnosis

A dermatologist can diagnose pityriasis alba by visually examining the spots and evaluating the person’s symptoms, medical history, and any topical medications used, such as retinoic acid or corticosteroids. In most cases, no specific test or lab exam is needed.

The doctor may also use a Wood’s lamp, a device that emits ultraviolet light, to help identify the type of skin lesion and rule out other conditions such as vitiligo, nevus depigmentosus, or fungal infections like tinea corporis or tinea versicolor.

Possible causes

There is no specific cause for pityriasis alba, but it is believed to be related to mild skin inflammation. The condition is not contagious.

Anyone can develop pityriasis alba, even without a history of skin problems, although it is more common in people with atopic dermatitis.

Treatment options

Treatment for pityriasis alba is not always necessary, as the spots often fade on their own over time, which may take several months to a few years.

However, if the spots do not fade, are extensive, or cause cosmetic concern, a dermatologist may recommend:

• Topical corticosteroid creams, such as hydrocortisone, to reduce inflammation, redness, and itching (pruritis), and to help even out skin tone;

• Moisturizing creams containing petrolatum (Vaseline) to relieve dryness and flaking;

• Immunosuppressive creams, such as tacrolimus ointment or pimecrolimus, to reduce inflammation in more persistent cases;

• Phototherapy with psoralen (PUVA) in cases with multiple or widespread lesions.

It is also recommended to apply sunscreen with SPF 30 or higher to the affected areas whenever exposed to sunlight, even on cloudy days. This helps prevent sunburn and reduces the contrast between normal and lighter skin tones.