6.1 A preliminary comparative study of high frequency muscle ultrasound and magnetic resonance imaging in 7 patients with juvenile dermatomyositis

Objective—To assess the value of ultrasound scans (USS) of the thigh in juvenile dermatomyositis (JDM) in comparison with magnetic resonance imaging (MRI). To correlate these findings with clinicopathological indicators of disease activity.

Methods—7 white patients with JDM (4 male, 3 female) had a high resolution muscle ultrasound examination. Mean age at onset was 6.8 years (range 1–15), 5/7 were scanned at diagnosis (within 6 months of diagnosis) and at follow up, 2/7 were scanned owing to chronic disease at 6 years from disease onset. Results of these scans were correlated with clinical, biochemical and histological markers. USS were correlated with MRI of the thigh in all patients.

Results—All 5 USS performed at diagnosis were abnormal. Most showed diffuse symmetrical hyperechogenicity affecting mainly the adductors, vasti and rectus femoris muscles. In several cases there was swelling of the affected muscles. These muscles were shown to be hyperaemic by colour Doppler imaging. After initial steroid treatment all USS showed a remarkable reduction in muscle echogenicity, muscle swelling, and vascularity. Two USS showed marked wasting and fatty infiltration after treatment and a major increase in subcutaneous adipose tissue. In one patient a clear progression from echogenic hyperaemic muscle through reduced echogenicity to fatty atrophy was seen over serial scans. One patient had calcinosis on follow up. The USS findings correlated well with MRI and biochemical markers of disease activity.

Conclusion—Musculoskeletal ultrasound is a safe, inexpensive, non-invasive means of supporting the clinical diagnosis of JDM and of monitoring disease progression, without needing sedation, which is often needed for an MRI in young children. Ultrasound findings appear to correlate well with other markers of disease activity.

6.2 FK-506 in the treatment of unresponsive juvenile dermatomyositis

Objective—To describe the efficacy and safety of FK-506 (tacrolimus) in three children with dermatomyositis.

Patients …