Pityriasis alba is sometimes a manifestation of atopic dermatitis in children, but can occur as an independent eczema. The cause is not known, but many hypotheses prevail regarding the origin of this childhood eczema. A relative vitamin and calcium deficiency from inappropriate food habits in kids seems to be the most plausible explanation, as pityriasis alba invariably occurs in the growing years in children.
Worm infestations, sun sensitivity, dry skin, and sensitization to various food preservatives have also been cited as the causes for this childhood disorder with loss of skin color.
Clinical Features of Pityriasis Alba
Both sexes are equally affected by Pityriasis alba. It occurs as a rounded scaly patch of loss of skin color. The patch may be red, pink or skin color to start with. Later the color starts fading and there is loss of pigmentation within the patch. There is minute scaling. The hypopigmented patch is more evident in dark skins.
The patches are 0.5 to 2 cm in diameter, and mainly limited to the face, though the neck, chest and forearms may also be involved in some cases.
The course is variable; some patches may remain for months and even for more than a year.
Tinea versicolor, the superficial yeast infection, early vitiligo and polymorphous light eruption are the conditions to be differentiated from pityriasis alba. In countries where it is prevalent, Hansen’s disease (leprosy) also comes as a differential diagnosis in P.alba.
Treatment of Pityriasis Alba
Response to treatment is often disappointing in pityriasis alba; the loss of color takes a long time to recover.
- The scaling can be reduced by the application of a bland emollient like mustela cold cream, Stelatopia cream or Veramed moisturizing cream.
- For chronic patches on the trunk, tar pastes will be useful
- Mild potency topical corticosteroids like clobetasone (not clobetasole, which is a superpotent steroid to be avoided in children and on the face), applied at night for a period of two weeks and stopped for one week and again applied for two weeks and so on is the best topical treatment for pityriasis alba.
- A sun protection cream of SPF 30 or above should be used if the child ventures out in the sun.
- A regular intake of milk and milk products, along with a multivitamin supplement and a balanced diet is helpful in reducing the chances of recurrences in most children.
- As prolonged use of topical steroids is not advisable on the face, steroid sparing topical calcineurin inhibitors tacrolimus and pimecrolimus can be used as safe alternatives.
Pityriasis alba creates anxiety in the dark skinned child and parents as it is confused with one of the major diseases causing loss of skin color, the vitiligo.
Reference
- Eczema, in Rook’s Textbook of Dermatology, 7th Edition, 2004
- Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology, Fifth Ed, 2005
Disclaimer
The information given in this article is for educational purpose only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.
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