[Pityriasis versicolor in children: a retrospective study of 164 cases]

Pityriasis versicolor is a superficial mycosis uncommonly reported in children. It occurs frequently in warm humid climates. Clinical diagnosis can be confirmed by mycology examination of a biopsy sample or a patch-test. The aim of our work was to assess the frequency of pityriasis versicolor in children in our region and ascertain the contribution of the cutaneous patch test and its diagnostic specificity.

A retrospective analysis was conducted in patients meeting the following inclusion criteria over a 5-year period: age < 14 years, clinical presentation compatible with pityriasis versicolor, a positive patch-test. Age, sex, clinical features and favoring factors were recorded for all patients. Patch tests were performed in a control group of age-matched children with eczema or vitiligo.

Pityriasis versicolor was diagnosed in 1,379 cases during the study period including 164 children (11.8 p. 100). Age varied from 5 months to 14 years (mean 11 years), with a slight female predominance. Facial lesions were the most frequent (n = 78; 47.5 p. 100), preferentially on the forehead (n = 53; 68 p. 100). An achromic and hypochromic aspect predominated (n = 118; 72 p. 100). The adhesive tape tests were negative in all controls.

Pityriasis versicolor is exceptional in children in our region. The adhesive tape test provides a specific diagnostic tool. Preferential facial localization and predominant achromic and hypochromic aspect are characteristic of childhood pityriasis versicolor in our region. These 2 features are also reported in the literature. Childhood cases suggests the pathogenic factors involved in pityriasis versicolor should be reconsidered. Pityriasis versicolor should be included in the differential diagnosis of childhood hypopigmentation of the face.