Incidence of childhood linear scleroderma and systemic sclerosis in the UK and Ireland.

OBJECTIVE

Childhood scleroderma encompasses a rare, poorly understood spectrum of conditions. Our aim was to ascertain the incidence of childhood scleroderma in its different forms in the UK and Ireland, and to describe the age, sex, and ethnicity of the cases.

METHODS

The members of 5 specialist medical associations including pediatricians, dermatologists, and rheumatologists were asked to report all cases of abnormal skin thickening suspected to be localized (including linear) scleroderma or systemic sclerosis (SSc) in children <16 years of age first seen between July 2005 and July 2007.

RESULTS

We received notification of 185 potential cases, and 94 valid cases were confirmed: 87 (93%) with localized scleroderma and 7 (7%) with SSc. This gave an incidence rate per million children per year of 3.4 (95% confidence interval [95% CI] 2.7-4.1) for localized scleroderma, including an incidence rate of 2.5 (95% CI 1.8-3.1) for linear scleroderma, and 0.27 (95% CI 0.1-0.5) for SSc. Of the 87 localized cases, 62 (71%) had linear disease. Of localized disease cases, 55 (63%) were female, 71 (82%) were classified as white British, and the patients' mean age when first seen in secondary care was 10.4 years. Of the 7 SSc cases, all were female, 6 (86%) were white British, and the mean age when first seen was 12.1 years. The median delay between onset and being first seen was 13.1 months for localized scleroderma and 7.2 months for SSc.

CONCLUSION

These data provide additional estimates of the incidence of this rare disorder and its subforms.