Pityriasis alba occurs mainly in infants, children and adolescents and is more often diagnosed among children with a darker complexion but may occur in individuals of all skin types. It is seen more frequently among male than female and among eczema patients. Prevalences of 8.4 % in India, 5,4 % in Ethiopia and 13.1 % (among children with eczema) in Nigeria have been published.
Etiology and pathogenesis
The etiology and pathogenesis are still poorly understood. Recent studies have found direct correlations between the incidence of pityriasis alba and atopy, the amount of sun exposure, and the frequency of bathing. Because it is usually asymptomatic, findings are often incidental. Without intervention, the lesions can persist for months to years and the hypo pigmentation usually does not clear with steroids but will clear in time. There is no difference in the number of melanocytes between lesional and normal skin which can be of help when diagnosing and differentiating pityriasis alba from other skin disorders with hypo pigmentation.
Pityriasis alba is a skin disorder characterized by asymptomatic, hypo pigmented, slightly scaling patches with unclear margins. It is one of the minor features of eczema and is primarily seen on the face and the trunk. Although treatment with emollients and mild topical corticosteroids may accelerate the repigmentation, they have limited efficacy. Pityriasis alba is more frequently seen among persons with a dark skin.
- Explain that the condition is not serious and will disappear in time.
- The skin can be treated regularly with an emollient cream or ointment like aqueous cream, coco butter or shea butter.
- Apply a mild topical corticosteroid cream like hydrocortisone 1% in case of inflammation.
- If available topical calcineurin inhibitors (TCI) like tacrolimus (0.03% and 0.1% ointment) or pimecrolimus (1% cream) may be used. The advantage is that they don’t cause cutaneous atrophy.
- ↑ 1.0 1.1 In SI, Yi SW, Kang HY et al. Clinical and histopathological characteristics of pityriasis alba. Clin Exp Dermatol 2009; 34: 591-7.
- ↑ 2.0 2.1 2.2 Jadotte YT, Janniger CK. Pityriasis alba revisited: perspectives on an enigmatic disorder of childhood. Cutis 2011; 87: 66-72.
- ↑ Dogra S, Kumar B. Epidemiology of skin diseases in school children: a study from northern India. Pediatr Dermatol 2003; 20: 470-3.
- ↑ Figueroa JI, Fuller LC, Abraha A et al. Dermatology in southwestern Ethiopia: rationale for a community approach. Int J Dermatol 1998; 37: 752-8.
- ↑ Nnoruka EN. Current epidemiology of atopic dermatitis in south-eastern Nigeria. Int J Dermatol 2004; 43: 739-44.
- ↑ Blessmann WM, Sponchiado de Avila LG, Albaneze R et al. Pityriasis alba: a study of pathogenic factors. J Eur Acad Dermatol Venereol 2002; 16: 463-8.
- ↑ 7.0 7.1 Lin RL, Janniger CK. Pityriasis alba. Cutis 2005; 76: 21-4.