Infection-induced panniculitis has been described in association with a broad range of microorganisms. Among those, viral panniculitis represents a minor category, with only a few anecdotal reports in the literature documenting viral infection in the subcutaneous fat. Herein, we report a woman in her 30s with seropositive rheumatoid arthritis on rituximab and prednisone, who presented with a 6-month history of progressive multisystem manifestations, including unintentional weight loss, fever, fatigue, myopathy, pancreatitis, and sensorineural hearing loss. She had indurated plaques on her thighs characterized by predominantly lobular panniculitis with chronic lymphohistiocytic inflammation. Molecular studies performed at the Centers for Disease Control and Prevention identified evidence of Enterovirus group with the highest identity of Coxsackievirus A9. Enterovirus RNA was also detected in the cerebrospinal fluid and muscle. Based on the findings, a diagnosis of disseminated enteroviral infection in the setting of B-cell depletion was rendered. To the best of our knowledge, this represents the first reported case of viral panniculitis with documentation of Coxsackievirus A9 in the skin. Since rituximab may be used for the treatment of autoimmune dermatological diseases, familiarity of the potential occurrence of severe enteroviral infections in the setting of immunosuppressive treatment is important for dermatopathologists.
Keywords: Coxsackievirus A9; enterovirus; rituximab; viral panniculitis.
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