Efficacy of hydroxychloroquine treatment for the skin manifestations of juvenile dermatomyositis.

Juvenile dermatomyositis (JDM) is the most popular subtype of juvenile idiopathic inflammatory myopathies clinically characterised by skin manifestations and myositis. Some patients with JDM present predominantly with skin symptoms without significant muscle weakness. Furthermore, some patients exhibit residual skin disease even after showing improvement of muscle symptoms with systemic glucocorticoids (GCs) and immunosuppressants. Topical GCs and/or tacrolimus are recommended for the patients with skin predominant JDM. Furthermore, systemic use of GCs and methotrexate (MTX) are indicated in refractory cases. However, some patients show refractory skin disease to even systemic use of GCs and MTX. Hydroxychloroquine (HCQ) has been reported to improve skin manifestations associated with JDM and is used globally for JDM. However, HCQ is not approved by the Ministry of Health, Labour and Welfare of Japan for treatment of JDM. Herein, we report two patients with JDM presenting with residual skin disease after taking systemic GC and immunosuppressants, which was successfully treated with HCQ. HCQ was effective for treating a case with skin symptoms without significant muscle weakness at relapse and for a case with residual skin symptoms after showing improvement of muscle symptoms with systemic GCs and immunosuppressants. No adverse events were observed in their clinical courses. Thus, HCQ may be an effective choice as an adjunctive therapy for refractory skin symptom-dominant JDM.