Dengue Fever

A 37 year old Indian male from Melaka who is a rubber tapper was admitted on the 4/8/2007 with the chief complain of fever for 5 days. The fever was continuous, high grade, associated with chills and rigor and there was also myalgia. He also had headache for 5 days. It was a frontal headache, moderate relieved on medication). There is no history to suggest respiratory infection or urinary tract infection. There is no shortness of breath, palpitations or chest pain. There was no bleeding tendency or bleeding from any sites. He has no rashes. There was no history of dengue reported in his working or housing area. There has no fogging been done in his area. He smokes 14 sticks per day for 20 yrs. He drinks 2 bottles of beer weekly for 15 years. He has no known drug or food allergies.
On examination, his vitals were normal. His temperature was under control with medication. He had pallor. He also had hepatomegaly, which was 5 cm below costal margin, 16 cm liver span, firm, non tender and smooth. On investigations, his platelet count was low (67,000). Urea was low (1.4mmol/l). APPT test was also high. Total protein was low (62g/l).
Diagnosis is Dengue Fever.
I learnt about the treatment of dengue fever which is
- Fluids
- Rest
- Antipyretics
- Monitor blood pressure, hematocrit, platelet count, level of consciousness

This patient had uncomplicated Dengue fever right?
Can you explain why fluids are needed for the treatment of Dengue fever? Do they lose fluid anywhere? If so, what is the pathophysiology behind that? The need for monitoring hematocrit and blood pressure is also related to this answer.

Fluids are needed to keep the optimal pulse volume and status. Normal saline is given.
In dengue haemorrhagic fever, there can be plasma leakage and haemorrhage.
This is how they lose fluid.
In plasma leakage, there will be a rise of more than 20% in haematocrit. A drop of more than 20% will happen following treatment with fluids as compared to baseline.
Blood pressure will be hypotension if a lot of blood is loss.