Childhood psoriasis: a study of 277 patients from China.

Objectives Psoriasis is common in childhood. The aim of this study was to present the clinical and epidemiological profile of childhood psoriasis in China. Methods A total of 277 childhood psoriasis patients younger than 16 years old were enrolled. Statistical analysis and heritability were performed using EPI INFO 6.0, SPSS 10.0 and Falconer's method. Results The median age was 11 years. The male : female ratio was 1 : 1.13. The median age of onset was 10 years. Of the patients, 48.7% had previous episodes of psoriasis. Of the 277 children with psoriasis, 68.6% had plaque-type psoriasis, 28.9% had guttate psoriasis, 1.1% presented pustular forms of psoriasis and 1.4% had erythroderma. The extensor surface of the extremities was the most frequently affected site in our patients, followed by the appearance of lesions on the scalp. A positive family history of psoriasis was found in 34.3% patients. The prevalence of psoriasis in first- and second-degree relatives was 7.0% and 1.0%, respectively. The heritability of psoriasis in first- and second-degree relatives was 72.67% and 55.18%, respectively. Conclusion Our epidemiologic studies offer the information about Han Chinese distribution, which provide clues to describe psoriasis in children.