Dengue haemorrhagic fever is diagnosed by-
Acute onset of high fever, presence of petechiae, epistaxis and platelet count > 2 lakh
Acute onset of high fever, positive tourniquest test, epistaxis or malena and malena and platelet count > 1.5 lakh
Acute onset of high fever 2 to 7 days, associated with hemorrhagic manifestation e.g. hemoptysis and platelet count less than 1.5 lakh
Acute onset of high fever, positive tourniquet test, bleeding gum and platelet count less than 1.0 lakh