From the Guidelines
Pityriasis alba is primarily caused by a combination of factors, including dry skin, sun exposure, and mild inflammation, with a possible association with atopic dermatitis, as noted in the 2014 guidelines of care for the management of atopic dermatitis 1. The exact cause is not fully understood, but it's believed to be related to:
- Dry skin (xerosis)
- Sun exposure leading to uneven skin pigmentation
- Mild eczema or atopic dermatitis, as suggested by the Hanifin and Rajka criteria and the UK Working Party diagnostic schemes 1 To manage pityriasis alba:
- Use a gentle, fragrance-free moisturizer daily
- Apply broad-spectrum sunscreen (SPF 30+) when outdoors
- Avoid excessive sun exposure and tanning
- For itching or inflammation, use a low-potency topical corticosteroid like hydrocortisone 1% cream for up to 2 weeks The condition is harmless and usually self-resolves within months to years, with the patches appearing lighter due to a temporary reduction in melanin production in affected areas, as implied by the discussion of atopic dermatitis diagnosis and assessment in the 2014 guidelines 1. Maintaining good skin hydration and sun protection can help prevent recurrence and promote even skin tone.
From the Research
Causes of Pityriasis Alba
The exact cause of Pityriasis Alba (PA) is still unknown, but several factors have been identified as potential triggers or risk factors:
- Atopy, xerosis, and mineral deficiencies are potential risk factors 2
- Sun exposure can exacerbate the condition, making lesions more visible 2, 3
- Poor cutaneous hydration may be a common theme for most risk factors, leading to inappropriate melanosis and hypopigmentation 2
- Beauty treatments and microorganisms have also been reported as possible triggering factors 4
- PA often coexists with atopic dermatitis and is considered one of its milder forms 5, 4, 6
Associated Factors
Several studies have found correlations between the incidence of PA and: