| Diffuse cutaneous systemic sclerosis | Sclerodactyly, skin tightness affecting the extremities, face, and eventually the trunk; hyperpigmentation, salt and pepper skin; telangiectasias; calcinosis; Raynaud phenomenon; nail-fold capillary abnormalities, digital pits or ulcers; interstitial lung disease; pulmonary hypertension; dysmotility affecting the gastrointestinal tract; joint contractures; scleroderma renal crisis. Positive antinuclear antibodies; positive anti-Scl-70 or anti-RNA polymerase III antibody. Other systemic sclerosis–specific antibodies are less common. |
| Scleredema | Skin tightness affecting nape of neck, interscapular region, upper back and face; usually spares hands, lower trunk and lower extremities. In children, there may be a history of preceding streptococcal infection; in adults, it is associated with poorly controlled diabetes mellitus or a paraproteinemia. Diagnosis can be confirmed on skin biopsy. |
| Nephrogenic systemic fibrosis | History of exposure to gadolinium-based contrast agents for magnetic resonance imaging scan, typically in patients with severe renal insufficiency. Initially there is cutaneous erythema and edema, followed by symmetric skin thickening over the extremities, which moves from distal to proximal but usually spares the face and head; ultimately painful patches, papules or nodules coalesce to form indurated, dermal plaques with a “cobblestone,” “woody” or peau d’orange appearance. Sclerodactyly is common; loss of skin appendages, hyperpigmentation and severe fixed joint contractures may develop. Raynaud phenomenon is absent and nail-fold capillaroscopy is normal. Diagnosis is confirmed on skin biopsy. |
| Diffuse fasciitis with eosinophilia | Starts with edema and erythema in the extremities, along with myalgias and arthralgias, soon followed by woody induration; associated with a peau d’orange appearance (Figure 1A). “Groove sign” is characteristic (Figure 1B). Sclerodactyly is uncommon. Peripheral blood and tissue eosinophilia decreases rapidly with treatment. Elevated erythrocyte sedimentation rate and C-reactive protein; polyclonal hypergammaglobulinemia. Creatine kinase is usually normal, but aldolase is often elevated before therapy. A full-thickness excisional biopsy from skin to muscle confirms the diagnosis (Figure 2). |
| Scleromyxedema | Associated with a benign monoclonal gammopathy. Cutaneous mucin deposition results in multiple flesh-coloured lichenoid papules, 2–3 mm in diameter, producing a typical “cobblestone” appearance, often on the glabella, neck, behind the ears, dorsum of the hands and the fingers (causing sclerodactyly), but sparing the palms. Over time, skin-fold thickening can lead to a leonine “mask-like” facies. Other features include Raynaud phenomenon, dysphagia, proximal myopathy, cardiopulmonary complications, and mild neurologic complications. Of untreated patients, 10% develop “dermato-neuro syndrome,” a potentially fatal complication characterized by fever, seizures and coma. |