A 56 years old male with sudden onset pedal oedema (pitting), h/o recent URTI -viral treated symptomatically. Oedema is more at daytime. When evaluated  in detail workup for liver function, kidney function, venous incompetence, anemia , inflammatory arthropathy and thryoid function negative.

Tried with diuretics, stokings oedema not resolving. How can we manage this case? Kindly suggest.