Scleroderma: How is this diagnosis made?
What is Scleroderma?
Scleroderma is one of the “connective tissue disorders” diagnosed and treated primarily by rheumatologists. In this condition, the interaction between autoimmunity, vascular disease and “fibrosis” results in the clinical features of the disease. Scleroderma is variable in the way it can affect patient’s overall health and quality of life. It can range from being an uncomfortable condition affecting the quality of life but not longevity, to being a very severe life-threatening disorder that can affect internal organ systems. A physician evaluating a patient with scleroderma or with possible scleroderma will often do a variety of screening tests that can help predict whether the condition is likely to affect internal organs.
Types of Scleroderma
A number of subtypes of scleroderma have been recognized.
In some patients, the disease is “localized” and purely a skin disorder, at times characterized by isolated patches of thickened scarred tight skin, to instances where that skin involvement becomes more widespread, but still does not extend to affect internal organs or cause vascular problems. In those patients the condition is referred to as “morphea” and it is not recognized as having the broader general health implications that are relevant to systemic sclerosis.
Within systemic sclerosis, two major forms are recognized, namely “limited” disease and “diffuse” disease. This broad categorization is based on the extent of skin involvement. In patients with limited disease, the skin involvement mostly affects the hands, possibly the forearms, but not extending above the elbows and there generally is sparing of the trunk. The face may be involved as well. In patients with “diffuse” scleroderma, the process often extends more proximally to the upper arms, thighs, chest wall and trunk. Patients with diffuse disease seem to be at higher risk for early lung involvement which is generally screened for proactively. They also seem to be higher risk for kidney involvement which can be catastrophic if left unrecognized, but can be easily screened for by checking simple urine analyses with some frequency, and checking blood pressures regularly (on the order of several times weekly) particularly early in the disease course. Although lung involvement or even kidney involvement can occur in patients with “limited” disease, it is less common as a rapidly progressive problem early in the disease course, although it is important not to overlook these potential complications.
Tests and Diagnosis
Of course, very early in the patient’s disease course it is not always possible to know with certainty whether they ultimately will have “limited” or “diffuse” disease. There are hints, however, from the history, physical examination and laboratory studies that can help us predict when patients are more likely to fall into one category or the other. Patients with limited disease often have a longstanding prior history of Raynaud’s phenomena. Patients with “diffuse” disease can at times present with puffy hands and rather rapid progression at least in the hands and forearms with only a short prior history of Raynaud’s phenomena. In many cases, however, it is impossible to be certain what course the disease will ultimately take. The rheumatologist will often order a panel of laboratory tests including “autoantibodies,” which are markers that can help predict one pattern of disease or another. Typically, the rheumatologist will order an ANA (antinuclear antibody, an antibody commonly found in many of the autoimmune diseases), as well as an Scl-70 antibody (positive in some patients with diffuse scleroderma), anticentromere antibody (generally felt to be a marker for “limited” scleroderma), and an antibody called RNA polymerase III, which seems to be a marker for diffuse scleroderma, and often predicts patients with more rapidly progressive skin disease, and also possibly higher risk for kidney involvement in whom blood pressures should be monitored with even greater vigilance.
Screening for Organ Involvement
There is no single algorithm as to how patients with established or even suspected scleroderma should be screened for organ involvement. The most important screening tool is a comprehensive history, which is a discussion between the patient and the physician, as well as a careful physical examination. Further tests that likely will be ordered will include blood tests and a urine analysis to assess basic parameters of health including whether or not anemia is present, the status of renal function, and usually also muscle blood tests to assess for whether there is any muscle inflammation which can occur in these disorders. Tests of lung and heart function are often requested, including pulmonary function studies (where a patient breathes into a tube and their lung function is assessed), often a chest x-ray or even high resolution chest CT scan, and usually an echocardiogram which can assess both the heart function, as well as the pressure in the arteries going from the heart to the lung (which helps screen for pulmonary hypertension). At times various GI tests may be requested depending on the patient’s symptoms. These tests are all done with an eye towards identifying problems when they are at early stage and possibly more easily treatable.
Future of Scleroderma
Physicians have learned a tremendous amount about disease patterns in scleroderma and how to identify potential problems early and address such emerging problems proactively. Although a specific “cure” for scleroderma is still elusive, there has been tremendous progress in addressing the individual organ system complications, and such progress is facilitated in the treatment of an individual patient by identifying problems early. Patients with scleroderma face tremendous challenges, but are seeing improvements in their quality of life, and the recognition of disease patterns and understanding of appropriate screening has helped make these improvements possible.
Dr. Robert Spiera is a rheumatologist and Director of the Vasculitis and Scleroderma Program at Hospital for Special Surgery. He is the principal investigator in several clinical trials and observational studies focusing on scleroderma and vasculitis.