Scleroderma, mixed connective-tissue disease and overlap syndromes: SAQ

This girl has the classic presentation of the juvenile localised scleroderma, the circumscribed morphea: the hard, the shiny, the ivory-coloured plaque with the violaceous lilac ring of the active inflammation, the slow enlargement, and the absence of the Raynaud phenomenon, the sclerodactyly, the nailfold changes and the internal organ involvement that would point to the systemic disease. The task is to confirm the localised diagnosis, to begin the methotrexate before the damage fixes, and to hold the contrast with the systemic sclerosis and the overlap syndrome. ^[6][9]

Question 1 (10 marks)

Outline how you classify and confirm the diagnosis in this eight-year-old girl with the indurated plaque. ^[6]

A full-mark answer places the lesion in the localised scleroderma family, names the Zulian classification subtypes, confirms the localised rather than the systemic disease, and identifies the linear subtype as the commonest and the one that harms the growing child. ^[8]

The classification and the family (3 marks). The lesion is the localised scleroderma (morphea), the disease confined to the skin and the subcutaneous tissue without the internal organ involvement. The Zulian classification, drawn from the seven hundred and fifty children, sorts the localised disease into five subtypes: the circumscribed morphea (the plaque, which this girl has), the linear scleroderma (the band), the generalised morphea, the pansclerotic morphea and the mixed morphea. The localised form is the commoner paediatric scleroderma and carries the better prognosis. ^[6]

The distinction from the systemic disease (3 marks). The absence of the Raynaud phenomenon, the sclerodactyly, the nailfold capillary changes and the internal organ involvement places the lesion in the localised family. The juvenile systemic sclerosis is defined by the proximal skin sclerosis with the internal organ disease, and it is rare in childhood. The PReS and ACR provisional criteria require the major criterion of the proximal skin sclerosis plus at least two minor criteria from the nine organ systems. The localised disease lacks these systemic features entirely. ^[2][1]

The confirmation and the subtype that matters (4 marks). The diagnosis of the typical morphea is clinical, with the induration, the lilac ring and the photography for the serial tracking, and the skin biopsy is reserved for the atypical lesion to exclude the mimics such as the lichen sclerosus and the eosinophilic fasciitis. The linear subtype is the commonest in children, around two-thirds, and the band that crosses a joint produces the contracture and the limb-length discrepancy, and the facial linear disease the en coup de sabre and the Parry-Romberg with the seizures and the uveitis. The fellow names the linear subtype as the one that demands the early methotrexate. ^[7]