Pityriasis alba

Pityriasis alba is a common skin condition causing hypopigmented facial patches in children and occasionally young adults.

This chapter is set out as follows:

• It is thought to be post-inflammatory in origin, possibly caused by a preceding eczema, however, this is rarely visible 

• Children and occasionally young adults 
• The problem is more apparent in summer, especially in skin of colour, because the patches don't tan as well as the surrounding skin

• Several round or oval hypopigmented patches on the face 
• The patches tend to be less well-defined than with vitiligo and most often affect the cheeks
• Wood's light - has little effect on the hypopigmentation of pityriasis alba, compared to vitiligo where the hypopigmentation become more pronounced 

• Provide a patient information leaflet

• In general no treatment is needed, or of help - the condition is self-limiting and the colour will return to normal over a number of months / years

• If there is any suggestion of underlying eczema eg itch, erythema and scale, use emollients regularly (2-3 times a day), and if needed weak topical steroids eg 1% hydrocortisone cream for short periods, or a steroid-sparing treatment such as pimecrolimus cream