Linear scleroderma ‘en coup de sabre’ and an unusual response to orthodontic treatment

Linear scleroderma is a type of localized scleroderma characterized by sclerotic skin lesions distributed in a linear, band-like pattern. When linear scleroderma appears on the head it is referred to as linear scleroderma ‘en coup de sabre’ owing to the resemblance of the skin lesions with the stroke of a sword. All localized forms have a 3:1 female predominance, except for linear scleroderma, in which males and females are affected equally. The ‘en coup de sabre’ subtype is estimated to have an incidence of 0.13 per 100,000 population.¹

It usually presents in the first or second decade of life as an atrophic-sclerotic band across the frontoparietal area with a varying degree of skin discoloration. The lesion is classically unilateral and does not extend below the eyebrow, although bilateral cases and cases involving the lower face have been described.²

The lesion arises following atrophy of skin, subcutaneous tissue, muscle and occasionally bone. Clinically, it is manifested by ivory-coloured plaques on the frontoparietal scalp and forehead. Lesions may extend to the nose, cheek, chin and neck.² ‘En coup de sabre’ is more often associated with ocular, oral and neurological abnormalities than other subtypes of linear scleroderma. In one case series, 7 out of 17 patients with craniofacial linear scleroderma were noted to have oral abnormalities: 2 patients had dental abnormalities, a further 3 had malocclusions, and 2 displayed tongue changes.³ Unfortunately, no further details of these abnormalities are given.