Medium- and long-term functional outcomes in a multicenter cohort of children with juvenile dermatomyositis

To evaluate functional outcomes in a cohort of patients with juvenile dermatomyositis (DM).

A retrospective inception cohort of patients diagnosed as having juvenile DM between January 1, 1984 and January 1, 1995 was established at 4 Canadian tertiary care pediatric centers. Informed consent was obtained. Each subject was interviewed by telephone or in person. The primary outcome was physical function, as measured by the Childhood Health Assessment Questionnaire (CHAQ). Additional outcomes were educational and vocational achievement, growth, development of calcinosis, patient satisfaction with outcome, and development of other illnesses. Data regarding illness presentation, treatment, and disease course were obtained through chart review.

Sixty-five of 80 patients (81%; 46 females and 19 males) could be contacted. The median followup time was 7.2 years (range 3.2-13.9 years), with a median age at followup of 13 years (range 7-26 years). Twenty-four patients (37%) had a monocyclic course, while the remaining 41 (63%) had a chronic continuous or polycyclic course. Sixty-two patients (95%) were treated with corticosteroids, while 41 (63%) received a second-line agent. Physical function was excellent, with a median CHAQ score of 0 (range 0-2.50). Eighteen patients had scores >0, and only 5 had moderate-to-severe disability, as defined by a CHAQ score >1.0. Females had higher CHAQ scores, and all but 1 of the patients with scores >0 were female (range 0-2.50; P = 0.015). Patients with a chronic continuous course also had higher CHAQ scores. Sixteen patients in the chronic continuous group had CHAQ scores >0 (range 0-2.50; P = 0.0009). Calcinosis developed in 22 patients (34%) and persisted to followup in 14. Development of calcinosis was not related to initial therapy, sex, or disease course, but was significantly associated with higher CHAQ scores (range 0-1.0 versus 0-2.5; P = 0.01). At the time of followup, 26 patients (40%) still had rash, 15 (23%) still reported weakness, and 23 (35%) continued taking medications, despite the fact that all were at least 3 years postdiagnosis. There was 1 death.

In general, patients in this cohort had favorable outcomes. Most had CHAQ scores of 0, and only 8% met our definition of moderate-to-severe disability. However, many patients continued to have chronic disease, persistent rash, and continued taking medications >3 years after diagnosis. Further research is needed to improve outcomes for patients with juvenile DM.