Scleroderma or systemic sclerosis (SSc) is a rare systemic autoimmune disease that is characterized by vasculopathy, immune dysregulation, and fibroblast dysfunction, which can result in fibrosis in various organ systems.1 SSc is broadly categorized into two subsets: diffuse cutaneous SSc and limited cutaneous SSc. Diffuse cutaneous SSc manifests as fibrotic disease, resulting in skin tightening and interstitial lung disease (ILD), and has extensive skin involvement where skin sclerosis extends to the elbows. Limited cutaneous SSc manifests as vascular disease, resulting in Raynaud phenomenon, pulmonary arterial hypertension and skin sclerosis confined to the distal extremities.
American Thoracic Society clinical practice guidelines define scleroderma-related ILD (SSc-ILD) as the presence of both SSc and ILD.2 SSc diagnosis should follow 2013 American College of Rheumatology and European Alliance of Associations for Rheumatology (ACR/EULAR) guidelines. The guidelines define the clinical criteria for SSc as proximal scleroderma and/or two or more of the following: sclerodactyly, pitting scars on the fingertips or loss of substance of the finger pad, or bibasilar pulmonary fibrosis.3 The newest ACR/EULAR guidelines expanded on this definition, adding a weighting system to minor diagnostic criteria, with a score ≥9 indicating SSc.4 Minor diagnostic criteria include skin thickening (puffy fingers [2] or sclerodactyly [4]), fingertip lesions (digital tip ulcers [2] or fingertip pitting scars [3]), telangiectasia (2), abnormal nailfold capillaries (2), pulmonary involvement (pulmonary arterial hypertension [2] or ILD [2]), Raynaud’s phenomenon (3), and presence of SSc-related antibodies (3).
ILD diagnosis is defined as the radiologic presence of reticulation, traction bronchiectasis, traction bronchiolectasis, honeycomb cysts, ground-glass opacities or air space consolidation, other interstitial lung abnormalities, or any of the recognized patterns of interstitial pneumonias reported in the context of SSc.2 Disease progression is marked by worsening dyspnea or cough, decline in forced vital capacity (FVC) or diffusing capacity of carbon monoxide (DLCO), and worsening in the extent or severity of ILD features on radiologic testing.
Expert consensus on SSc-ILD diagnosis recommends that all patients with SSc be screened for ILD using chest auscultation, spirometry with DLCO, high-resolution computed tomography (HRCT), and/or autoantibody testing.5
References
- Varga J. Systemic Sclerosis (Scleroderma) and Related Disorders. In: Jameson J, Fauci A, Kasper D, Hauser S, Longo D, Loscalzo J, eds. Harrison's Principles of Internal Medicine. 20 ed. McGraw-Hill Education; 2018.
- Raghu G, Montesi SB, Silver RM, et al. Treatment of Systemic Sclerosis-associated Interstitial Lung Disease: Evidence-based Recommendations. An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. Sep 29 2023;doi:10.1164/rccm.202306-1113ST
- Preliminary criteria for the classification of systemic sclerosis (scleroderma). Subcommittee for scleroderma criteria of the American Rheumatism Association Diagnostic and Therapeutic Criteria Committee. Arthritis Rheum. May 1980;23(5):581-90. doi:10.1002/art.1780230510
- van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthritis Rheum. Nov 2013;65(11):2737-47. doi:10.1002/art.38098
- Rahaghi FF, Hsu VM, Kaner RJ, et al. Expert consensus on the management of systemic sclerosis-associated interstitial lung disease. Respir Res. Jan 9 2023;24(1):6. doi:10.1186/s12931-022-02292-3
