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cutaneous scleroderma (morphea)
systemic scleroderma
| • | limited disease (CREST, acrosclerosis) |
| • | diffuse disease (PSS = progressive systemic sclerosis) |
epidemiology:
| • | occupational exposure to silica dust: relative risk 25 |
| • | silicone implants: no increased risk (retrospective study) |
| • | peak occurrence age 40-50’s; female:male ratio most pronounced during childbearing years (female sex hormones may influence disease susceptibility) |
pathology:
| • | a “vasculopathy”: affects small vessels, is not a vasculitis |
| • | a proliferative, obliterative process |
| • | fibrosis: increased deposition of collagen and other ground substance |
autoantibodies:
| • | ANA are present at clinical presentation in 95% of patients |
| • | autoantibodies specific for systemic sclerosis: |
| • | anti-centromere: 80% of patients with CREST |
| • | anti-Scl 70 (topoisomerase type 1): 26-76% patients with PSS Progressive Systemic Sclerosis |
| • | rarely occur together; titers are not followed |
“limited” scleroderma:
| • | i.e. without truncal involvement |
| • | CREST falls within this subset |
| • | usually have Raynaud’s for 5-10 years before other signs of scleroderma seen |
| • | most, gradually develop features of CREST |
| • | relatively good prognosis but may develop: |
| • | pulmonary hypertension (even without fibrosis) |
diffuse systemic sclerosis:
| • | criteria include skin thickening proximal to metacarpophalangeal joints or 2 minor |
| • | rapid onset following appearance of Raynaud’s |
| • | runs a 2-3 year course with often irreversible changes |
| • | course is highly variable, but once a remission occurs, relapse is uncommon |
pulmonary – 2 pathologic processes:
| 1. | fibrosing alveolitis progressing to interstitial fibrosis |
| 2. | vasculopathy of pulmonary vessels à pulmonary hypertension |
| • | most patients have both processes |
| • | interstitial fibrosis more likely to be severe in PSS |
| • | isolated pulmonary hypertension is associated with CREST |
| • | best detected by PFT’s (restrictive defect) or high res CT |
| • | CXR insensitive, may show bilateral lower lobe fibrosis: “honeycomb lung” |
| • | isolated pulmonary hypertension without significant interstitial fibrosis has the worst prognosis of all of the visceral problems (no meds alter the prognosis which is uniformly fatal in 6 months to 5 years) |
GI:
| • | most common GI symptoms = dysphagia and heartburn |
| • | early – abnormal function of smooth muscle in distal 2/3 of esophagus secondary to neuromuscular dysfunction |
| • | later – smooth muscle atrophy and fibrosis |
treatment of esophageal dysmotility:
| • | small frequent meals, elevate head of bed, proton pump inhibitors |
| • | cisapride: prokinetic drug used to stimulate esophageal muscle contraction; limited effectiveness |
| • | distal esophageal strictureà periodic dilatation |
| • | careful with Ca channel blockers (mentioned above to treat Raynauds): decrease LES pressure, and therefore aggravate reflux symptoms |
renal:
| • | renal crisis – previously the most feared visceral complication (renal failure almost inevitable) |
| • | key = early detection and rapid normalization of BP (i.e. home monitoring) |
distinctive nail changes:
| • | inverse pterygium distal groove obliterated, skin remains attached, painful (probably a consequence of fingertip ulceration and scarring) |
| • | nail beaking a nail change that occurs as a consequence of the atrophy of the fingertip soft tissues |
treatment:
| • | penicillamine: an immunomodulating agent, also interferes with cross linking of collagen |
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