From the Guidelines
Scleroderma and CREST syndrome are diagnosed based on specific clinical and laboratory criteria, with the 2013 ACR/EULAR classification criteria being the most widely accepted guidelines, as there is no update provided in the given evidence 1. The diagnostic criteria for systemic sclerosis (scleroderma) include skin thickening of the fingers extending proximal to the metacarpophalangeal joints as a sufficient criterion, or a total score of 9 or more points from the following:
- Skin thickening of the fingers (puffy fingers: 2 points; sclerodactyly: 4 points)
- Fingertip lesions (digital tip ulcers: 2 points; fingertip pitting scars: 3 points)
- Telangiectasia (2 points)
- Abnormal nailfold capillaries (2 points)
- Pulmonary arterial hypertension and/or interstitial lung disease (2 points)
- Raynaud's phenomenon (3 points)
- Scleroderma-related autoantibodies including anti-centromere, anti-topoisomerase I, and anti-RNA polymerase III (3 points) 1. For CREST syndrome, a limited form of systemic sclerosis, diagnosis is based on the presence of at least three of the five features:
- Calcinosis
- Raynaud's phenomenon
- Esophageal dysmotility
- Sclerodactyly
- Telangiectasia. Laboratory tests, including antinuclear antibodies (ANA) and specific autoantibodies like anti-centromere antibodies (common in CREST) and anti-Scl-70 (common in diffuse scleroderma), are important for diagnosis, as mentioned in the EULAR recommendations for the treatment of systemic sclerosis 1. Additional testing may include:
- Nailfold capillaroscopy
- Pulmonary function tests
- Echocardiography
- High-resolution CT scans to assess organ involvement, which is crucial in managing the disease, as recommended by the EULAR guidelines for the treatment of systemic sclerosis 1.
From the Research
Diagnostic Criteria for Scleroderma and CREST
- Scleroderma is a multisystem disorder characterized by skin thickening and vascular abnormalities, with approximately 80% of patients being females, and one-half presenting before the age of 40 2.
- The American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) 2013 criteria are used to diagnose SSc, which includes elements such as calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia 3.
- CREST syndrome is a clinical entity associated with systemic sclerosis, which meets at least three of the five clinical features: calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia 3.
- Calcinosis seems to be less common in SSc and its association with other clinical features is characteristic of CREST syndrome, making it a key element of CREST syndrome 3.
- Three major disease subsets are recognized based on the extent of skin disease: limited disease (also known as CREST syndrome), diffuse disease, and localized disease 2.
Autoantibodies in Scleroderma and CREST
- Anti-Scl-70 antibodies are detected in systemic sclerosis only, with a specificity of 100% and sensitivity of 40% 4.
- Anti-centromere antibodies are present in cases of complete or incomplete CREST syndrome, and seem to be markers of a form of scleroderma with a different course and prognosis than anti-Scl-70 antibodies 5.
- The presence of anti-Scl-70 antibodies correlates with the presence of antinuclear antibodies and the extent of cutaneous involvement 4.
- Anti-centromere antibodies are usually associated with high titers, and are frequently found in patients with Raynaud's phenomenon and CREST syndrome 6.