Unusual musculoskeletal manifestations of Lyme disease.

We report on the imaging features of musculoskeletal abnormalities in a 52-year-old woman suffering from Lyme disease presenting with acrodermatitis chronica atrophicans (ACA). The patient developed recurrent attacks of migratory asymmetrical oligoarthritis, involving articular and peri-articular structures, including the metatarsophalageal (MTP) joints, scapular bone, thoracic spine, elbow, gluteal area, knee, ankle and metacarpophalangeal (MCP) joints. Six months after the first symptoms, Magnetic Resonance Imaging (MRI) showed bone marrow oedema within the proximal phalanx of the right fifth toe, adjacent to an ACA rash. A year after the onset of the disease, swelling at the right scapular region occurred, and MRI showed osseous, periosteal and soft tissue involvement of the superior margin of the right scapula and adjacent rib. On MRI of the spine, there was bone marrow infiltration with irregular delineation of the anterior corner of the thoracic vertebrae 4 to 6, corresponding to an osteoblastic bony lesion on radiographic examination. This case report is unique, because MRI documentation of bony abnormalities and periarticular soft tissue swelling, accompanying an attack of ACA has never been reported previously. Moreover, involvement of the osseous spine and the scapular bone have never been described in the radiological literature.