The term scleroderma means a thickening or hardening of the skin associated with an increase in its collagen content. Thickening of the skin also occurs in association with other conditions, such as porphyria or the carcinoid syndrome. In these conditions the lesion is called pseudoscleroderma.
The generic term ‘scleroderma’ should not be used, as systemic sclerosis and morphoea are distinct entities. Systemic sclerosis has both cutaneous and systemic features, whilst morphoea is confined to the skin.
Females are more frequently affected in a ratio of 3 : 1. It most commonly presents in young patients as a plaque of thickened red or blue skin, sometimes showing central pallor; the skin over the trunk and limbs is most frequently involved. A more superficial and widespread pattern of disease affects the trunk in middle-aged females. Children are affected by linear lesions seen on the skull and over the face and tissues underlying the skin may also be involved, producing facial hemiatrophy.
Plaques evolve to produce waxy, thickened skin that cannot be easily separated from the underlying tissue. Individual plaques may enlarge or new lesions appear over an interval and resolution is associated with hyperpigmentation that may never totally fade. Involvement of the limb may be associated with widespread and severe induration of the skin, muscle pain and joint stiffness.
Generalized cutaneous disease is rare.
The early inflammatory changes, if severe and associated with oedema and induration, may be limited
by systemic steroids and azathioprine. It is difficult to treat well-established cutaneous disease.
In two-thirds of patients, Raynaud’s phenomenon may be present for years or even decades prior to the development of other clinical features. Severe ischaemia associated with this disease may lead to severe ulceration, gangrene and a loss of digits.
Typically the skin in systemic sclerosis is bound down to underlying structures and the fingers taper (known as sclerodactyly or acrosclerosis). Fibrotic changes around the joints may produce flexion deformities and prevent fine movements. A binding down of facial skin may produce beaking of the nose, a fixed facial expression, radial furrowing of the lips and limitation of mouth opening. Mat-like telangiectases on the face or hands and some proximal spread of skin thickening complete the usual picture. Calcium deposits are sometimes extruded from the skin over digits (CR(E)ST syndrome, see p.404). Thickening of the skin and pigmentary changes are often seen at the base of the neck or over the cervical spine and shoulders.
The disease may sometimes present as puffiness or oedema of the hands or feet, with preceding or accompanying attacks of Raynaud’s phenomenon, though circulatory impairment may not be evident. A more explosive onset with widespread or universal skin thickening and more extensive visceral disease is less common.
DIFFERENTIAL DIAGNOSIS. Systemic sclerosis-like disease is seen in the toxic oil syndrome, polyvinyl chloride disease, eosinophilia-myalgia syndrome due to tryptophan therapy, bleomycin therapy and graft-versushost disease.
TREATMENT. Severe Raynaud’s phenomenon may be helped by charcoal, chemical or preheated thermal glove warmers or electrically heated gloves. Nifedipine may limit the attacks. Severe ulceration or imminent gangrene may be prevented by the intravenous infusion of prostaglandin E, or prostacyclin. Dryness of the skin associated with hair loss, damage to sweat glands and sebaceous glands may respond to emollients and soap substitutes.
Dermatomyositis and polymyositis
These uncommon diseases affect blood vessels, muscle and skin in a varying fashion.
Dermatomyositis when seen in childhood often has a marked vascular component. Disease in adults aged 40- 60 years affects the skin and muscle tissue together. Proximal myopathy, often associated with malignant disease per se; and non-specific skin changes have sometimes been mislabelled as dermatomyositis. This misdiagnosis has probably given a falsely high incidence of associated malignant disease (10-25%) that can be seen in adults with dermatomyositis. Recently Coxsackie B virus has been isolated from muscle tissue.
The rash is often very distinctive and may display features of photosensitivity. Fingers show ragged cuticles and haemorrhages with dilated and altered nail-fold capillary changes (Fig. 20.14). Erythematous, blue plaques are evident over the dorsal aspect of the fingers, more especially over the small joints, with a similar but streaked appearance over the metacarpophalangeal joints. Mild scaling
may accompany these findings.
Scaling and erythema are seen at the elbow, and on occasions blue/red discoloration and reticulate patterning of the skin over the wrists, knees, feet, arms or thighs are seen.
Facial changes may include a marked erythema resembling sunburn, but inflammation of the eyelids or heliotrope coloration suggest the true diagnosis. Other exposed skin, e.g. the ‘V’ of the neck or the upper arms, may show erythema and sunburn-like changes that may also cause confusion. Marked cutaneous changes may occur in the absence of muscle disease. Typically, however, patients experience a proximal muscle weakness, noticeable when getting off a lavatory or combing the hair; dysphagia and respiratory muscle involvement are rare.
An underlying malignancy should be looked for. The malignancy may precede, accompany or follow the rash. Measurement of muscle enzyme levels and electromyogram (EMG) studies or muscle biopsy are helpful in the diagnosis and in following disease progress .
The prevention of joint contractures is very important in the childhood pattern of disease and soft-tissue calcification may regress with time. In adults, prednisolone with or without azathioprine or methotrexate is given for muscle disease (see p.951) which will often clear cutaneous features. Sun screening and topical corticosteroid therapy may help to limit changes in the skin in those patients with predominantly cutaneous disease.