eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2018-05-16 6 4 72 74 10.12691/ajmcr-6-4-5 AJMCR2018645 article Maria Pereira maria.pereira2@bcm.edu 1 2 Catherine Mary Healy 2 3 Carrie A. Mohila 4 Monica Marcus 4 4 Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX Department of Pathology & Immunology, Baylor College of Medicine, Texas Children's Hospital, Houston, TX We present the first case of cat-scratch disease described to trigger juvenile polymyositis. A 15-year-old male presented with a prolonged febrile illness. He had been diagnosed with cat-scratch disease 4 weeks earlier based on his exposure to kittens and serologic testing. Treatment with antimicrobials provided partial relief. He continued to have unremitting fever and developed headache, jaw pain, blurry vision, myalgias and impaired ambulation. Imaging studies were most consistent with myositis of the lower extremities and muscles of mastication. A muscle biopsy of anterior tibialis muscle confirmed a diagnosis of polymyositis. Patient had an excellent response upon initiation of immunosuppressive treatment. Juvenile polymyositis is a rare disease and should be part of the differential diagnosis of patients presenting with prolonged fever and severe myalgias with normal muscle enzymes, particularly following a bartonella henselae infection. http://pubs.sciepub.com/ajmcr/6/4/5/ajmcr-6-4-5.pdf juvenile polymyositis idiopathic inflammatory myopathy masticatory myositis Bartonella henselae cat-scratch disease