Dermatomyosite juvénile de survenue précoce et de présentation inhabituelle

Abstract

A 13-month-old infant presented with an edema of the upper lip, 4days after receiving amoxicillin-clavulanate. The patient was treated with betamethasone and an antihistamine. Progression was marked by the appearance of a white edema of the periorbital area and the upper lip, with purpuric lesions, aphthoid ulcerations, and a drooping head. Very high muscle enzymes, a myogenic electromyogram, and hypertrophic cardiomyopathy were found and diagnosis of JDM was retained. The patient was treated with a high dose of corticosteroids and methotrexate. Before the installation of dysphagia, dysphonia, and axial hypotonia, the bolus of cyclophosphamide was administered, with clear improvement. Corticosteroids and methotrexate were then kept over the long term. The originality of this observation of JDM resides in the very young age of onset of the disease, its unusual cutaneous signs including labial edema extending to the regions around the eyes, its severe muscle manifestations causing axial hypotonia, and finally, in its association with hypertrophic cardiomyopathy. Early initiation of treatment (12 days after the onset of symptoms) greatly improved the prognosis of this form of JDM, which is very severe and refractory to first-line therapy.