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]

Question 2 (10 marks)

Discuss the definitive management of the active localised scleroderma, and contrast it with the approach to a child with the juvenile systemic sclerosis and a child with the mixed connective-tissue disease. [9]

A full-mark answer reproduces the methotrexate-based therapy for the localised disease, contrasts it with the organ-specific therapy for the systemic disease, and frames the mixed connective-tissue disease as the management of the dominant feature with the pulmonary hypertension surveillance. [1][10]

The management of the active localised disease (4 marks). The methotrexate is the first-line systemic therapy, given at fifteen milligrams per square metre per week, by the subcutaneous or the oral route, with the folic acid. The systemic corticosteroid is added as the bridging for the active and the severe disease, as the intravenous methylprednisolone pulse of thirty milligrams per kilogram per day capped at one gram for three consecutive days repeated monthly for three months, or the oral prednisolone at one milligram per kilogram per day capped at fifty milligrams tapered over the months. The physiotherapy and the occupational therapy prevent the contracture, and the reconstructive surgery is deferred until the disease is quiescent. The fellow treats the disease activity and not the skin score. [9][7]

The management of the juvenile systemic sclerosis (3 marks). The systemic disease is managed by the multidisciplinary team. The skin disease is treated with the methotrexate, the mycophenolate mofetil or the cyclophosphamide, by the severity and the organ involvement. The vascular disease is treated with the calcium channel blocker for the Raynaud, the phosphodiesterase five inhibitor for the severe disease, and the bosentan for the prevention of the new digital ulcers. The lung is screened for the interstitial lung disease and the pulmonary hypertension at the baseline and the regular intervals. The renal crisis is treated with the angiotensin-converting enzyme inhibitor even in the renal failure, and the high-dose corticosteroid above fifteen milligrams per day is avoided because it precipitates the crisis. [1][5]

The management of the mixed connective-tissue disease (3 marks). The high-titre anti-U1-RNP antibody is confirmed first. The disease is treated by the dominant feature: the arthritis with the methotrexate and the hydroxychloroquine, the myositis with the corticosteroid and the immunosuppression, and the Raynaud with the calcium channel blocker. The pulmonary hypertension is screened with the echocardiography and the pro-B-type natriuretic peptide at the baseline and the regular intervals, and the right heart catheterisation confirms it. The pulmonary arterial hypertension therapy is begun early, because the pulmonary hypertension is the complication that decides the prognosis. [10][11]