Juvenile dermatomyositis: a retrospective review of a 30-year experience.

BACKGROUND: Children with juvenile dermatomyositis (JDMS) have variable initial presentations.

OBJECTIVE: Our purpose was to evaluate the epidemiology trends, presenting clinical features, laboratory data, and outcome of patients with JDMS.

METHODS: A total of 16 patients were identified at Geisinger Medical Center by a 30-year retrospective chart review.

RESULTS: Sex ratio, age at diagnosis, and outcome were similar to data published in previous studies. However, certain trends were noted. The most common initial physical examination findings were an extremity rash (94%) and periungual erythema (75%). New associations of JDMS that were uncovered included the findings of pruritus (38%) and a psoriasiform scalp dermatitis (25%). Nonspecific laboratory elevations were the most common initial laboratory changes (erythrocyte sedimentation rate, lactate dehydrogenase, and aspartate aminotransferase). Tubuloreticular inclusions as found on electron microscopy of muscle biopsy specimens were present in all 3 patients tested. One patient with tubuloreticular inclusions had otherwise normal muscle biopsy findings on hematoxylin-and-eosin staining. Two of the 16 patients had cutaneous findings of JDMS but did not exhibit muscle involvement after long-term follow-up at 4 and 5 years.

CONCLUSION: Our study confirms that the initial physical and laboratory findings in patients with JDMS may be nonspecific. The heliotrope rash and Gottron papules classically associated with dermatomyositis appeared less commonly than an extremity rash and periungual erythema. Creatinine kinase and aldolase levels may not be elevated on initial presentation. Pruritus, a psoriasiform scalp dermatitis, and tubuloreticular inclusions found on muscle biopsy electron microscopy should be additional factors to consider. The long-term follow-up in 2 patients without muscle involvement lends support to the existence of amyopathic dermatomyositis.