Early symptoms of DF and DHF are indistinguishable, but DHF is associated with hemorrhagic manifestations, plasma leakage resulting from an increased vascular permeability, and thrombocytopenia (<100,000 platelets/mm3). Thrombocytopenia is not necessarily restricted to severe dengue, and minor bleeding may occur in mild infections, which can be severe in those with peptic ulcer disease (9). Plasma leakage is characterized by haemoconcentration (haematocrit increase of 20%), development of ascites, or pleural effusion.