(1997; 132 pages) [French] [Spanish]
Pityriasis alba (patchy hypochromia)
Pityriasis alba (patchy hypochromia) affects over 80% of children living in rural areas of developing countries. The disease is characterized by oval or round, scaly, hypochromic lesions in light-exposed areas. Its etiology is obscure. In developed countries, pityriasis alba, which generally is seen with slight scaling, is often a manifestation of atopy (inflammation causes residual hypopigmentation, which is aggravated by the use of topical corticosteroids). In developing countries, skin dryness, nasal discharge and poor hygiene may favour subclinical bacterial proliferation and parakeratosis. These in turn are clinically manifested as fine desquamation and hypochromia.
While hypochromia is only a minor cosmetic problem, it is often perceived as a health priority. Management should be addressed first to explaining the nature of the disease and its lack of relation to other common conditions in developing countries such as vitamin deficiencies, intestinal parasite infections or other infections. It is also necessary to point out that the disease itself is not contagious. Emollients can be prescribed. In developing countries, a topical preparation consisting of 60% petroleum jelly and 40% zinc oxide with 2% clioquinol powder and 0.5% coal tar is used for this condition. The preparation should be applied at night and washed off in the morning. Treatment usually has to be maintained for 4-6 weeks.