Pityriasis alba L30.59

Discrete white spots on the face (mostly lateral parts of the cheeks), which are conspicuously prominent on the first tan, without symptoms, very discreetly scaling; more rarely on the extensor sides of the forearms.

In a study with 56 patients (In SI et al. 2009) 18% showed a previous atopic dermatitis, so that a minus variant of an atopic eczema can be assumed in these patients. About 1/3 of the patients do not show 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 a large area, e.g. on the upper arm extensor sides, more rarely on the lower extremity.

Mostly inconspicuous, round or multibanded due to confluence, low pityriasiform scaling, pale or white, 0.5-2.0 cm spots that sometimes have marginal accentuation. 10% of patients develop only a single lesion. Minor pruritus may occur. In fair skin, the appearances tend to be discrete and are often overlooked. In dark skin, the lesions are more prominent due to the difference in colour between affected and unaffected skin. In an initial phase, a slight reddening of the spots 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 stains can persist for months, possibly even years. Eventually they heal spontaneously.

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. Pediatric Dermatol 12: 197-198
3. Galan EB (1998) Pityriasis alba. Cutis 61: 11-13
4. In SI et al (2009) Clinical and histopathological characteristics of pityriasis alba. Clin Exp Dermatol 34:591-597
5. Wolf R et al (1985) Extensive pityriasis alba and atopic dermatitis. Br J Dermatol 112: 247