Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Hypodermal Compressibility as a Diagnostic Test for Eosinophilic Fasciitis.

Kissin1,  Eugene Y., York2,  Michael R., Simms3,  Robert W.

Boston University, Boston, MA
Boston University Medical Ctr, Boston, MA
Boston University School of Medicine, Boston, MA

Purpose:

Eosinophilic fasciitis (EF) is an autoimmune, fibrotic disorder that presents with painful swollen extremities. Though there are clinical characteristics that may distinguish it from diffuse systemic sclerosis (dSSc), frequently a deep wedge biopsy of the skin and fascia is felt to be necessary to confirm the diagnosis. We sought to determine whether high resolution B-mode ultrasound could distinguish forearm involvement by EF from similar fibrotic diseases such as systemic sclerosis, and diabetic cheiroarthropathy (DMc), and from controls with normal skin and fascia.

Methods:

Consecutive patients with clinically diagnosed EF, DMc, dSSc, and fibromyalgia (FM) (FM with normal skin and subcutaneous tissue) were recruited from a rheumatology clinic over a period of 2 years to undergo ultrasound evaluation of the forearm. A GE LOGIQ e ultrasound unit with an L12 probe was used to evaluate the more clinically affected mid-dorsal forearm. The hypodermal tissues between the deep dermal interface and the muscle edge at the groove formed between the extensor digitorum and extensor carpi radialis was evaluated in short axis for the following variables: tissue depth with no transducer pressure (gel layer used to "float" the transducer to avoid any pressure), tissue depth with maximal tissue compression by transducer, and tissue echogenicity measured by densitometry (NIH Image). Dermal thickness was also measured. Tissue compressibility was calculated as (non-compressed tissue depth–compressed tissue depth)/non-compressed tissue depth. Statistical analysis was by T-test.

Results:

The following numbers of patients were studied in each group: EF–8, dSSc–23, DMc–8, FM–8. Hypodermal percent compressibility was significantly less in EF compared with the other groups (means ± SD): EF–9 ± 7, dSSc–30 ± 13 (p<0.004 vs. EF), DMc–29 ± 20 (p<0.02 vs. EF), and FM–29 ± 14 (p<0.003 vs. EF) (Figure). Hypodermal atrophy, measuring less than 4mm in thickness, was apparent in patients with EF–3/8 (38%), dSSc–7/23 (30%), and DMc–4/8 (50%), but not FM–0/8 (0%). DMc or dSSc patients only had < 20% hypodermal compressibility if they also had hypodermal atrophy, while all but one EF patient had compressibility of less than 20% regardless of hypodermal atrophy. Hypodermal tissue average echogenicity did not differ between the 4 groups (EF=155 ± 21 densitometry units (du), dSSc=145 ± 16 du, DMc=157 ± 12 du, FM=149 ± 17 du, p=NS). Dermal thickness also did not vary significantly between the 4 groups (EF=1.3mm ± 0.2, dSSc=1.4mm ±0.3, DMc=14mm ±0.3, FM 13mm ±0.3, p=NS).

Figure 1.

Figure 2.

Conclusions:

Ultrasound can easily measure hypodermal compressibility. Our data suggest that reduction in hypodermal compressibility to less than 20% in non-atrophied hypodermis can be used to distinguish EF from dSSc and DMc, potentially obviating the need for wedge biopsy.

To cite this abstract, please use the following information:
Kissin, Eugene Y., York, Michael R., Simms, Robert W.; Hypodermal Compressibility as a Diagnostic Test for Eosinophilic Fasciitis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1624
DOI: 10.1002/art.29390

Abstract Supplement

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