Chapter 164: Other Connective Tissue Diseases

CONNECTIVE TISSUE DISEASE

DEFINITION

Heterogeneous disorders that share certain common features, including inflammation of skin, joints, and other structures rich in connective tissue; as well as altered patterns of immunoregulation, including production of autoantibodies and abnormalities of cell-mediated immunity. While distinct clinical entities can be defined, manifestations may vary considerably from one pt to the next, and overlap of clinical features between and among specific diseases can occur.

SYSTEMIC SCLEROSIS (SCLERODERMA, SSc)

DEFINITION AND PATHOGENESIS

SSc is a multisystem disorder characterized by thickening of the skin (scleroderma) and distinctive involvement of multiple internal organs (chiefly GI tract, lungs, heart, and kidney). Pathogenesis unclear; involves immunologic mechanisms leading to vascular endothelial damage and activation of fibroblasts.

CLINICAL MANIFESTATIONS

• Cutaneous: edema followed by fibrosis of the skin (chiefly extremities, face, trunk); telangiectasia; calcinosis; Raynaud’s phenomenon

• Arthralgias and/or arthritis

• GI: esophageal hypomotility; intestinal hypofunction, gastric antral vascular ectasia (GAVE)

• Pulmonary: interstitial lung disease (ILD), pulmonary arterial hypertension, alveolitis

• Cardiac: pericarditis, cardiomyopathy, conduction abnormalities

• Renal: hypertension; renal crisis/failure

Two distinct subsets can be identified:

1. Diffuse cutaneous SSc: rapid development of symmetric skin thickening of proximal and distal extremity, face, and trunk. At high risk for development of visceral disease early in course.

2. Limited cutaneous SSc: often have long-standing Raynaud’s phenomenon before other features appear; skin involvement limited to fingers (sclerodactyly), extremity distal to elbows, and face; generally associated with better prognosis but can be associated with pulmonary arterial hypertension; a subset of limited SSc has features of CREST syndrome (calcinosis, Raynaud’s, esophageal dysmotility, sclerodactyly, telangiectasias).

EVALUATION

• History and physical examination with particular attention to blood pressure (heralding feature of renal disease).

• Laboratories: ESR, ANA (anticentromere pattern associated with limited SSc), specific antibodies may include anti-topoisomerase I (Scl-70), (UA). An increased range of autoantibodies correlating with specific clinical features have become recognized (Table 353-3, HPIM-20).

• Radiographs: CXR, barium swallow if indicated, hand x-rays may show distal tuft resorption and calcinosis.

• Additional studies: ECG, echo, PFT, consider skin biopsy.

TREATMENT