A rare case of suspected lupus erythematous panniculitis as the presenting skin feature of juvenile dermatomyositis: A case report

Abstract

Juvenile dermatomyositis is a rare autoimmune myopathy of childhood, associated with systemic vasculopathy, primarily affecting the capillaries. Panniculitis is seen histologically in about 10% of patients with dermatomyositis; however, its clinical presentation is rare, with only 30 cases presented in the literature to date. The histopathology overlaps with other inflammatory disease states, and is almost identical to the panniculitis seen in lupus erythematous panniculitis. In the cases with both panniculitis and dermatomyositis, skin and muscle inflammation is usually the first clinical manifestation. We present a case of a 16-year-old female with panniculitis as the initial presenting feature of juvenile dermatomyositis in the context of a prior diagnosis of indeterminate colitis.

Keywords: Juvenile dermatomyositis; inflammatory bowel disease; lupus erythematosus panniculitis; lupus panniculitis; panniculitis.

Figure 1.

Multiple painful gray-brown subtly indurated and depressed round nodules most prominent on the anterior (a) and lateral thighs bilaterally (b and c), initially diagnosed as lupus erythematosus panniculitis on skin biopsy before other clinical manifestations of juvenile dermatomyositis presented.

Figure 2.

Deep skin and subcutaneous biopsy of the lateral thigh: scanning magnification (a) shows a lobular panniculitis and a patchy superficial and deep dermal perivascular, perifollicular, and periadnexal lymphoplasmacytic inflammatory infiltrate without accompanying interface or epidermal changes (Hematoxylin & Eosin ×20). Higher magnification (b) shows the lymphoplasmacytic inflammation within lobules of subcutaneous fat and small foci of fat necrosis (Hematoxylin & Eosin ×100).

Figure 3.

Magnetic resonance imaging demonstrates diffuse extensive patchy hyperintense T2 signal intensity seen in multiple muscles of the shoulders, upper arms, chest wall, abdominal wall, bilateral paraspinal regions (a), bilateral psoas, and bilateral thighs (b), keeping with myositis.