Systemic sclerosis

Systemic sclerosis

In this disorder the skin becomes hard as connective tissues thicken. Early in the condition, T-helper cells dominate the inflammatory infiltrate in the dermis and cause fibroblasts to proliferate and produce more hyaluronic acid and type I collagen. In addition there is intimal thickening of arterioles and arteries. These processes are not confined to the skin, but involve many other organs, including the gut, lungs, kidneys and heart, leading to their dysfunction and to death.

The cause of systemic sclerosis is unknown but many, apparently unrelated, pieces of the complex jigsaw are now beginning to come together. A systemic sclerosis-like syndrome is a feature of the chronic graft-vs.-host disease sometimes seen after bone marrow transplantation  and prolonged, untreated porphyria cutanea torda. Similar syndromes have been reported following ingestion of adulterated rapeseed oil in Spain and dimerised L-tryptophan for insomnia and treatment with the antitumour agent, bleomycin. Environmental factors may also be rel-evant in isolated cases; changes like those of systemic sclerosis have affected workers exposed to polyvinyl chloride monomers, trichlorethylene and epoxy resins and in those subjected for years to severe vibration. 

Presentation

Most patients suffer from Raynaud’s phenomenon  and sclerodactyly. Their fingers become immob-ile, hard and shiny. Some become hyperpigmented and itchy early in their disease. Peri-ungual telangiec-tasia is common.

As the disease progresses, sclerosis spreads to the face, scalp and trunk. The nose becomes beak-like, and wrinkles radiate around the mouth (Fig. 10.8– 10.10). Most have abnormalities of the gut including dysphagia, oesophagitis, constipation, diarrhoea and malabsorption. Fibrosis of the lungs leads to dyspnoea, and fibrosis of the heart to congestive failure. The kidneys are involved late, but this has a grave prognosis from malignant hypertension.

Complications

Most complications are caused by the involvement of organs other than the skin, but ulcers of the fingertips and calcinosis are distressing (Fig. 10.11). Hard skin immobilizes the joints and leads to contractures.

Differential diagnosis

Other causes of Raynaud’s phenomenon are given in Table 11.5. The differential diagnosis includes chilblains  and erythromelalgia. The sclerosis should be distinguished from that of wide-spread morphoea, porphyria cutanea tarda, mixed connective tissue disease, eosinophilic fasciitis, dia-betic sclerodactyly and an acute arthritis with swollen fingers. Rarely the disease is mimicked by progeria, scleromyxoedema, amyloidosis or carcinoid syndrome. Changes like those of progressive systemic sclerosis affect workers exposed to polyvinyl chloride mono-mers or to severe chronic vibration, and are also seen in chronic graft-vs.-host reactions after bone marrow transplants.

Investigations

The diagnosis is made clinically because histological abnormalities are seldom present until the physical signs are well established. Laboratory tests should include a fluorescent antinuclear antibody test and the evaluation of the heart, kidney, lungs, joints and muscles. Barium studies are best avoided as obstruc-tion may follow poor evacuation. Other contrast media are available. X-rays of the hands, measurement of muscle enzymes and immunoglobulin levels, and a blood count, ESR and test for the scleroderma-associated antibody Scl-70 are also worthwhile.

Treatment

This is unsatisfactory. The calcium channel blocker nifedipine may help Raynaud’s phenomenon. Systemic steroids, salicylates, antimalarials and long-term penicillin are used, but are not of proven value. D-penicillamine has many side-effects, especially on renal function. Physiotherapy is helpful; photo-pheresis is experimental. Recently, there have been promising reports of the efficacy of ultraviolet A-1 (340 – 400 nm) phototherapy for affected skin in systemic sclerosis.