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Systemic Sclerosis
Essentials
- Systemic sclerosis is characterized by small vessel injuries, immunological abnormalities, and induration and shrinking of connective tissue.
- Scleroderma refers to the skin manifestations of systemic sclerosis. Systemic sclerosis and scleroderma are often used as synonyms.
- Systemic sclerosis is classified into a diffuse and a limited form.
Epidemiology
- The prevalence of systemic sclerosis is 100-200 cases per one million people.
- The incidence is highest in women aged 30-50 years.
Symptoms
- Raynaud's phenomenon (see Raynaud's Phenomenon (Rp) or White Finger Disease) can be observed in almost every patient, and it often precedes other symptoms of the disease. The condition may lead to ulcerations and scars on the fingertips and toes.
- Skin changes occur, especially in the face, hands and feet. First there is swelling of the skin, then thickening and finally atrophy (picture 1). In the limited form of the disease the skin lesions occur in the face and in the extremities distal to the knees and elbows, whereas in diffuse systemic sclerosis the skin symptoms are more widespread.
- Telangiectasies may be seen.
- 20-30% of all patients have arthralgia and myalgia.
- There may be symptoms from the gastrointestinal tract, particularly dysphagia, reflux oesophagitis and oesophageal strictures. Malabsorption, obstipation and faecal incontinence may be present.
- Lung fibrosis, pulmonary hypertension
- Heart failure, arrhythmias
- Proteinuria, impaired renal function and elevated blood pressure are not rare. The most severe renal complication is the scleroderma renal crisis characterized by highly elevated blood pressure, rapidly progressing renal failure and microangiopathic haemolytic anaemia.
Investigations and diagnosis
- When suspecting systemic sclerosis, the following investigations are recommended to be take within primary health care: ESR, CRP, basic blood count with platelet count, antinuclear antibodies, creatinine, chemical urinalysis.
- The combination of Raynaud's phenomenon, swollen fingers and a positive result in antinuclear antibody test is regarded as a "red flag", which should lead to suspecting early systemic sclerosis and a consultation within specialized health care.
- The diagnosis of systemic sclerosis is confirmed within specialized care. The most important further investigations include determination of specific autoantibodies (anticentromere antibodies and type I topoisomerase, i.e. Scl-70 antibodies), videocapillaroscopy and, if needed, skin biopsy.
- ESR is often moderately increased in systemic sclerosis, but CRP is normal or slightly elevated. Basic blood count is usually normal; leucopenia and thrombocytopenia occur clearly less frequently than in SLE. Antinuclear antibodies are found in about 90%. Nucleolar staining pattern is typically either speckled or nucleolar.
- Centromere antibodies are found in those with the limited disease form (previously the CREST syndrome , i.e. calcinosis, Raynaud's phenomenon, oesophageal hypomotility, sclerodactyly, teleangiectasies). This disease form is associated with the risk of elevated pulmonary artery pressure.
- Type I topoisomerase antibodies are usually associated with the diffuse disease and an increased risk of pulmonary fibrosis.
- Videocapillaroscopy is an important method in distinguishing between primary and secondary Raynaud's phenomenon. Changes in the nailfold capillaries are found in over 80% of patients with systemic sclerosis, and the abnormalities correlate with the severity of the disease.
- A chest radiography helps to assess the pulmonary status. High-resolution computed tomography and pulmonary function tests are often necessary further investigations.
- Subcutaneous calcifications and acrolysis in the fingers, both typical for the disease, may be found in radiographs of the hands and feet.
- With respect to the gastrointestinal system, the most important investigation is oesophagogastroduodenoscopy.
Prognosis
- Favourable when the disease is confined to the skin
- Pulmonary hypertension and respiratory or renal failure are factors that compromise the prognosis.