Pityriasis alba L30.59

Discrete, conspicuously prominent, asymptomatic, very discreetly scaling, white patches on the face (usually on the sides of the cheeks); less frequently on the upper parts of the trunk and the extensor sides of the forearms.

In a study of 56 patients (In SI et al. 2009), 18% had a previous history of atopic dermatitis, meaning that a minus variant of atopic eczema can be assumed in these patients. Approximately 1/3 of the patients showed no signs of atopy at the time of diagnosis.

3-10 years, rarely adults, dark skinned individuals are affected significantly more often. No gender preference.

Mostly on the cheeks and forehead, but also over large areas, e.g. on the upper arm extensor sides, less frequently on the lower extremities and upper trunk. They are more pronounced in people with darker skin.

Mostly inconspicuous, round or multi-arched due to confluence, slightly pityriasiform scaling, light or white, 0.5-2.0 cm large patches which sometimes have a marginal accentuation. 10% of patients develop only a single lesion. There may be slight itching. In light skin, the lesions tend to be discreet and are often overlooked. In dark skin, the lesions are more prominent due to the difference in color between affected and unaffected skin. In the initial phase, slight lesional erythema may be noticed.

S.a. Pseudoleukoderma atopicum

S.a. Pigmentary pityriasis alba

S.a. Pityriasis simplex faciei

Histologically, a discrete superficial interstitial dermatitis is found, with a reduced epidermal pigmentation, whereby the number of melanocytes is not reduced. Ultrastructurally, degenerative changes in the melanocytes can be detected with a reduction in the melanosomes.

The treatment of patients initially consists of convincing them that the disease is self-limiting and not dangerous.

It is advisable to reduce exposure to the sun and wind, use sunscreen regularly and reduce the frequency and temperature of baths.

Externally, only local skin care measures are recommended, e.g. using a mild day cream. Wash as little as possible to minimize irritation (avoid soaps and syndets). Cleanse the face with a hydrophilic oil or an O/W emulsion.

The spots can persist for months or even years. Ultimately, most cases heal within a year.

1. Blessmann Weber M (2002) Pityriasis alba: a study of pathogenic factors. J Eur Acad Dermatol Venereol 16: 463-468
2. Dhar S (1995) Pigmenting pityriasis alba. Pediatr Dermatol 12: 197-198
3. Galan EB (1998) Pityriasis alba. Cutis 61: 11-13
4. Givler DN et al. (2024) In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. PMID: 28613715
5. In SI et al. (2009) Clinical and histopathological characteristics of pityriasis alba. Clin Exp Dermatol 34:591-597

6. Lee D et al. (2008) A Case of Extensive Pityriasis Alba. Ann Dermatol 20:146-148.

7. Wolf R et al. (1985) Extensive pityriasis alba and atopic dermatitis. Br J Dermatol 112: 247