•We present the fourth documented potential case suggestive of “true” neuromyelitis optica spectrum disorder (NMOSD) meeting the current criteria associated with dengue infection.•Most reported cases of acute dengue infection presenting with a core clinical phenotype listed in the 2015 NMOSD diagnostic criteria were not tested for AQP4-IgG antibody.•Cases with acute DENV-infection with a neurological manifestation presented with a spinal cord phenotype, the majority with a LETM.•AQP4-IgG status might be helpful in a suggestive neurological presentation associated with dengue infection and subsequent decisions regarding long term immunotherapy. : Neuromyelitis Optica Spectrum Disorder can be associated with parainfectious and post-infectious triggers. Dengue virus infection is one of the most common arbovirus infections in the world, and may present with neurological manifestations. : We present a case of DENV-associated with LETM and positive aquaporin-4 IgG, and a systematic review of published cases. : Medline (Ovid) and PubMed were search through June 2021, for case reports, series and observational studies that described patients with DENV-associated LETM and/or NMOSD. : An adolescent girl who had recently immigrated from a Dengue-endemic region presented with a LETM with high positive AQP4-IgG titer and seropositive DENV IgM/IgG antibodies. She responded well to steroids and subsequently started maintenance rituximab for her NMOSD diagnosis. Literature review: 22 publications describing 27 patients met inclusion criteria. In addition to this case, three published cases met current criteria for NMOSD with serological evidence of acute DENV infection. : It is unknown whether there is a pathophysiological association between DENV infection and NMOSD. Regardless, if an immune-mediated event is suspected, particularly NMOSD, appropriate immunotherapy should be considered early. Decision regarding long term immunotherapy may depend on index of suspicion of true NMOSD, and this is where AQP4-IgG status and follow-up is helpful.