Pigmented purpuric dermatosis: clinicopathologic characterization in a pediatric series

Pigmentary purpuras (PPs) are a group of chronic disorders of unknown origin seldom described in children. With this study we sought to better characterize PP eruptions, including clinical evolution and management. A retrospective chart review from 2003 to 2013 querying characteristics of children with a biopsy-proven diagnosis of PP in the Centre Hospitalier Universitaire Ste-Justine dermatology clinic (Montreal, Quebec, Canada) was performed. Follow-up was obtained through telephone interviews. Descriptive statistical analysis was used. Of the 17 subjects, 8 were male and the mean age of onset was 9 years. PP was asymptomatic in 11 patients, pruritic in 3, and of cosmetic concern in 3. Schamberg's disease was the most frequent subtype in 12 cases. Resolution of PP was found in 13 cases with a median duration of less than 1 year (range 6 months-9 years). Five patients experienced spontaneous clearing without treatment, and improvement was observed in 75% of cases treated with topical corticosteroids and 100% with narrowband ultraviolet B (nbUVB). No associated disease, significant drug exposure, or contact allergens were found. Those findings support that PPs in children are idiopathic, chronic eruptions that can benefit from watchful waiting, although topical corticosteroids or nbUVB are may be useful if the patient or family desires faster resolution. This study was limited by its small size, its retrospective nature, and selection and recall bias.