• | characterized by rapid onset of symmetric woody induration of the extremities |
• | 50% of cases preceded by an episode of unusual exertion/strenuous exercise |
• | the skin has a characteristic “puckered” appearance (in addition to involving the fascia, this disease is usually associated with an inflammatory process in the septa of the subcutaneous fat) |
• | groove sign vertically linear depressions following the course of vessels occurs between muscle groups (e.g. between bicep and tricep on the medial upper arm) |
• | still uncertain whether EF is a distinct entity or if it represents a deep form of scleroderma |
ddx:
• | scleroderma...but EF has: |
• | absence of Raynaud’s, (-) ANA, peripheral eosinophilia |
• | rare visceral involvement (i.e. esophageal dysmotility or pulmonary fibrosis) |
• | lesions usually confined to the extremities (sparing fingers and toes) |
• | minimal dermal changes and preservation of skin appendages on biopsy |
• | eosinophilia myalgia syndrome: identical cutaneous induration |
histology: flame figures = collagen fibers encrusted with intensely eosinophilic granular material representing major basic protein (but may be found in any condition associated with an intense eosinophil infiltrate)
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