Nail Psoriasis: A Systematic Evaluation in 313 Children with Psoriasis

Background/Objectives Little information is available on the prevalence and clinical aspects of nail involvement in children with psoriasis. The objective of this study was to evaluate the prevalence and clinical aspects of and the risk factors for nail involvement in French children with psoriasis. Methods We performed a multicenter, cross-sectional study in 23 French dermatology centers. All children seen during the 1-year study were systematically included. Clinical features of the nails were collected. Association with clinical aspects of the disease and comorbidities were evaluated. Results Of 313 children with psoriasis (mean age 9.1 ± 4.2 yrs; 149 boys, 164 girls), 31.1% had familial psoriasis and 30% had severe psoriasis. The mean age at onset was 6.1 ± 3.7 years. Nails were involved in 32.3% of children. The main clinical aspects were pitting (69.1%) for fingernails and onycholysis (40.0%) and pachyonychia (27.5%) for toenails. All of the fingers were involved at similar frequencies, whereas the big toe was involved twice as often as the others (p < 0.005). Nail involvement was associated with male sex (p < 0.001), palmoplantar psoriatic (p < 0.001), severity of disease (p = 0.003), and psoriatic arthritis (p = 0.03). Conclusion The prevalence of nail involvement was 32.3% in children with psoriasis. Clinical aspects in children are reported, as well as clinical associations. As in adults, nail psoriasis is closely associated with psoriatic arthritis.