We have been treating successfully a number cases of acute high fever due to dengue ( positive NS1) and other viral fever ( undiagnosed type) in same family members with single dose of prednisolone 20 to 40 mg with famotidine coverage. Many physician hesitate to use prednisolone but actually it has no harm.
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.researchgate.net/publication/374889763_Single_Dose_of_Prednisolone_Can_Cure_Fever_of_Dengue_in_Short_Time&ved=2ahUKEwjV1qPum92OAxUxyzgGHZRXM2sQFnoECBoQAQ&usg=AOvVaw3ehq1QKcch-4a5Y7rByKtx