acyclovir and Dermatomyositis

Human herpes virus-6 (HHV-6) reactivation is a well-recognised complication following haematological stem cell transplantation, but it is novel in the context of combination immunomodulatory therapy for autoimmune disease. We report a case of severe anterograde amnesia caused by HHV-6 encephalitis in a young female patient on rituximab, azathioprine and prednisolone for dermatomyositis (DM). The use of targeted biologic treatments for systemic autoimmune connective tissue diseases (CTDs) is increasing, particularly when refractory to conventional management. The anti-CD20 B cell depleting monoclonal antibody, rituximab is now increasingly used, often in combination with conventional immunomodulatory treatments, in certain autoimmune neurological conditions and systemic CTDs including DM. Physicians should be aware of the possibility of HHV-6 in those who develop encephalitis while CD20 B cell deplete, especially in the presence of additional immunomodulatory therapies. Prompt diagnosis and treatment of HHV-6 encephalitis with evidence-based anti-viral therapy may help reduce the extent of irreversible morbidity such as amnesia.

Topics: Acyclovir; Adult; Amnesia, Anterograde; Antiviral Agents; Azathioprine; B-Lymphocytes; Dermatomyositis; Encephalitis, Viral; Female; Herpesvirus 6, Human; Humans; Immunologic Factors; Lymphocyte Depletion; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Prednisolone; Rituximab; Roseolovirus Infections

Chronic cutaneous varicella zoster virus (VZV) infection has not been previously reported or characterized as a complication of dermatomyositis. Two patients with non-malignancy-associated dermatomyositis, treated with long-term prednisone and methotrexate, developed persistent, painless ulcers ultimately established to be secondary to chronic VZV. The absence of pain or a history suggestive of acute VZV, and the lack of characteristic histopathology, resulted in a lengthy delay in diagnosis. Polymerase chain reaction and tissue immunohistochemistry were positive for VZV, and treatment with valacyclovir resulted in complete clearance. Diagnostic testing for VZV should thus be considered in the evaluation of ulcerative lesions in patients with dermatomyositis. The increased incidence of acute VZV in combination with the nature and duration of immunosuppressive treatment in this patient population may be contributory.

Topics: Acyclovir; Aged; Antiviral Agents; Chronic Disease; Dermatomyositis; Female; Herpesviridae Infections; Herpesvirus 3, Human; Humans; Immunosuppressive Agents; Skin Diseases, Viral; Valacyclovir; Valine