What Causes White Pityriasis (Pityriasis Alba) on the Face?

We often observe that many children readily develop pityriasis alba on their faces—appearing as scattered, patchy areas. Many parents do not pay sufficient attention to this condition. Common underlying causes of facial pityriasis alba in children include trace element deficiencies and malnutrition, both of which may predispose to infection and trigger the development of facial pityriasis alba. Below, we outline the primary reasons why children develop pityriasis alba on the face.

What Causes Pityriasis Alba on the Face?

The exact etiology of pityriasis alba remains unclear. Nelson Textbook of Pediatrics classifies pityriasis alba as an eczematous disorder, suggesting it represents a mild, chronic form of dermatitis leading to post-inflammatory hypopigmentation. However, its occurrence is not restricted solely to individuals with atopic (allergic) constitutions. Furthermore, no conclusive evidence links pityriasis alba to intestinal parasitic infections such as ascariasis; therefore, administering antiparasitic treatment solely based on the presence of facial hypopigmented patches lacks scientific justification. Factors including excessive sun exposure, malnutrition or vitamin deficiencies, xerosis (dry skin), and frequent bathing may all contribute to disease onset.

What Is Pityriasis Alba?

Pityriasis alba, also known as “simple pityriasis,” “facial xerotic pityriasis,” “streptococcal pityriasis,” or “streptococcal erythema,” is colloquially referred to as “peach blossom tinea” or “worm spots.” It is a dermatitis characterized by dry, fine, bran-like scaling and hypopigmentation.

This condition predominantly affects children aged 3–16 years, typically beginning in spring, worsening during summer, and gradually resolving by autumn. Lesions most commonly occur on the face; however, in some cases, they may also involve the neck, shoulders, and upper limbs. The number and distribution of white patches are variable; lesions are usually round or oval. Initially, they present as faint erythematous macules—sometimes with slightly elevated borders—which subsequently resolve completely, leaving behind pale, ill-defined, ash-gray hypopigmented patches measuring approximately 3–5 cm in diameter. These patches exhibit fine, bran-like scale on their surface. Affected children are typically asymptomatic, though occasional mild pruritus may occur.

The above provides an overview of the causes and characteristics of facial pityriasis alba. We hope this information proves helpful.