MUSCULOSKELETAL
Etiology
Autoimmune connective tissue disease characterized by fibrosis, vascular damage, and immune dysregulation.
Associated with environmental triggers (silica dust, organic solvents) and genetic predisposition (HLA genes).
Pathogenesis
Immune activation → endothelial injury → fibroblast stimulation → excessive collagen deposition in skin, blood vessels, and internal organs (lungs, heart, GI tract, kidneys).
Clinical Features
Skin: Thickened, shiny, tight skin (especially hands/face), digital ulcers, Raynaud’s phenomenon.
Limited form (CREST): Calcinosis, Raynaud’s, Esophageal dysmotility, Sclerodactyly, Telangiectasia.
Diffuse form: Widespread skin and internal organ involvement (lungs → fibrosis, kidneys → crisis).
Diagnosis
Autoantibodies: Anti-centromere (limited form), Anti–Scl-70 / anti-topoisomerase I (diffuse form).
Nailfold capillaroscopy shows capillary dropout.
Organ-specific testing (PFTs, echocardiogram, renal function).
Treatment
Symptomatic and organ-specific:
• Raynaud’s: calcium channel blockers (nifedipine)
• Fibrosis: immunosuppressants (mycophenolate, cyclophosphamide)Hypertension/renal crisis: ACE inhibitors.
Avoid cold and smoking.