Author: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1997. Updated January 2016.
Pityriasis alba is a low-grade type of eczema/dermatitis that primarily affects children.
The name refers to its appearance: pityriasis refers to its characteristic fine scale, and alba to its pale colour (hypopigmentation).
Pityriasis alba is common worldwide with a prevalence in children of around 5%.
The cause of pityriasis alba is unknown.
Researchers have not reached any conclusions about the relationship of pityriasis alba to the following:
Classic pityriasis alba usually presents with 1 to 20 patches or thin plaques.
Typically, each area of pityriasis alba goes through several stages.
None are known.
Pityriasis alba can be confused with several other disorders that cause hypopigmentation.
To exclude these, investigations may include:
No treatment is necessary for asymptomatic pityriasis alba.
The development or prominence of pityriasis alba can be reduced by avoiding exposure to sunlight.
Pityriasis clears up after a few months, or in some cases persists for up to two or three years. The colour gradually returns completely to normal.
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