Follow-up of juvenile dermatomyositis (JDM) patients has demonstrated the impact of the disease on several organs in the long term.

As there is little information on the long-term outcome of JDM, we aimed to assess long-term outcomes in a series of JDM patients.

After selection of JDM patients, a consultation with a dermatologist and a rheumatologist was held for each patient. Cutaneous, muscle, and disease damage was assessed using different validated scores including the abbreviated Cutaneous Assessment Tool (aCAT), 8-muscle Manual Muscle Testing (MMT8), Childhood Myositis Assessment Scale (CMAS), Myositis Damage Index (MDI), Childhood Health Assessment Questionnaire (CHAQ), and Health Assessment Questionnaire (HAQ). Long-term disease outcomes were recorded including growth and pubertal development, educational and vocational achievement, and development of comorbidities.

Seven patients were included in the study. After a mean follow-up of 14.9±8.8 years, the mean aCAT score was 0.57±1.4 and only one patient had a positive aCAT activity score. The mean aCAT damage score was 1.4±1.3 and five (71%) patients had a score of ≥1. Five (71.4%) patients had normal muscle strength with an MMT8 score of >72, and none had severe muscle weakness (MMT8 ≤32, and CMAS<35). The mean total extent of damage according to the MDI was ≥1 in five (71%) patients and mainly involved the skin. Two (29%) patients had mild disability according to the CHAQ/HAQ disability index. In terms of quality of life, no patient had a score of<40 (1 SD below the mean for healthy controls).

Based on validated cutaneous and musculoskeletal scores, our study demonstrated the good functional outcomes of JDM at long-term follow-up.