Ultrasound assessment of subcutaneous compressibility: a potential adjunctive diagnostic tool in eosinophilic fasciitis.

BACKGROUND: Eosinophilic fasciitis (EF) is an autoimmune, fibrotic disorder described initially with scleroderma-like skin changes where deep soft tissue sampling that includes fascia is frequently felt to be necessary to confirm the diagnosis.

OBJECTIVE: The objective of this study was to distinguish forearm involvement by EF from other fibrosing diseases and from control subjects with normal skin and fascia using B-mode ultrasound.

METHODS: A cross-sectional study over a 4-year period in which clinically involved forearm skin of consecutive patients with EF (n = 12), diabetic cheiroarthropathy (n = 8), diffuse systemic sclerosis (n = 23), and control subjects (n = 8) was evaluated by 12-MHz, B-mode ultrasound for degree of subcutaneous tissue compressibility, and this finding was compared with the criterion standard of clinical diagnostic criteria for each disease process.

RESULTS: Subcutaneous compressibility in EF was significantly reduced when compared with diffuse systemic sclerosis and with control subjects. Subcutaneous thinning was observed in some patients with EF (4/12), diabetic cheiroarthropathy (4/8), and diffuse systemic sclerosis (6/23), but not in control subjects. Diabetic cheiroarthropathy and diffuse systemic sclerosis patients with subcutaneous thinning had less than 20% subcutaneous compressibility, whereas only 1 of 12 EF patients had compressibility of more than 20% regardless of subcutaneous thinning.

CONCLUSIONS: A 12-MHz, B-mode ultrasound may be used to measure subcutaneous compressibility, thereby serving as an adjunct tool in distinguishing EF from diffuse systemic sclerosis, especially when tissue sampling is less feasible or when the result of tissue sampling is equivocal.