Antihistone antibodies in linear scleroderma variants

Background Linear scleroderma occurs as two clinically distinct variants: the frontoparietal en coup de sabre type, and the torso-extremity type. Antihistone antibodies (AHAs), which traditionally are markers for drug-induced lupus, may also be linked to linear scleroderma. Methods Retrospective review of all patients presenting with linear scleroderma who had AHA titers measured. Results A total of 35 patients were identified. Twenty patients with linear scleroderma of the torso and/or extremities comprised 14 pediatric patients (≤ 18 years old; positive AHA, 10/14 = 71%; positive ANA, 3/13 = 23%) and six adults (four positive AHA; five positive ANA). Among the 15 patients with frontoparietal linear scleroderma, en coup de sabre type, 11 were pediatric patients (positive AHA, 5/11 = 45%; positive ANA, 4/11 = 36%) and four were adults (1 positive AHA/ANA). Conclusion The two clinical variants of linear scleroderma are not only clinically distinct, but also may be serologically different. The AHA titers may be related to the extent of involvement as well as disease activity in linear scleroderma.