Imatinib-induced dermatomyositis sine dermatitis - a rare case report

Abstract

Idiopathic Inflammatory Myopathies are rare conditions with several heterogeneous disease subtypes. They can range from limited muscle or skin involvement to severe, systemic, life-threatening disease. Although the etiology is unknown, some evidence suggests a role for external agents, particularly drugs. Herein, we present a case of a 71-year-old woman with chronic myeloid leukemia who developed imatinib-induced dermatomyositis sine dermatitis. The presentation was predominantly muscular, characterized by proximal muscle weakness and myalgia of the lower limbs, with positive anti-Mi2a antibodies. Spontaneous recovery was observed after drug discontinuation, without the need for immunosuppressive therapy. This is the first confirmed description of an imatinib-induced dermatomyositis sine dermatitis. It reflects the importance of a high awareness from rheumatologists and hematologists to accurately anticipate and identify similar situations.

Keywords: autoantibodies; dermatomyositis sine dermatitis; imatinib mesylate; inflammatory myopathies; proximal muscle weakness.

Figure 1

Muscle thigh magnetic resonance imaging scans, in axial plans, revealing fatty infiltration between the fibers (filled arrow) and atrophy of the biceps femoris and semitendinosus muscles (unfilled arrow). (A, B) were acquired in LAVA Flex and T2 sequences, respectively.

Figure 2

Clinical course of the Imatinib-induced Dermatomyositis sine dermatitis.