Differential diagnosis of Common Febrile Syndromes Dengue fever Malaria Leptospirosis Clinical Manifestations Dengue Fever: Sudden high grade fever, headache, retro-orbital pain, myalgias , arthralgias . Weakness, rash, nausea, vomiting, petechiae , epistaxis, gingival bleeding Dengue hemorrhagic fever: Fever 2-7 days, hemorrhagic manifestation, thrombocytopenia, increased vascular permeability Dengue shock syndrome: DHF + hypotension, pulse pressure < 20 mmHg, or frank shock Fever, shaking chills, headache, myalgias , fatigue, nausea, vomiting, orthostatic hypotension Septicemic phase: Fever, headache, chills, myalgia, conjunctival suffusion, abdominal pain, nausea, vomiting, diarrhea, rash Immune phase (Weil syndrome): cardiac arrhythmias, hemodynamic collapse, hemorrhage, jaundice, liver failure, aseptic meningitis, pulmonary insufficiency, renal failure