DENGUE FEVER

 aedes 

from google

Dengue is one of the most important arthropod-borne viral diseases in term of human morbidity and mortality.Nowdays, dengue has become an important public health problem.It affects tropical and subtropical regions around the world,predominantly in urban and semi urban areas.

THE CLINICAL COURSE OF DENGUE INFECTION

After the incubation period, dengue begin abruptly and will follow by 3 main phase : febrile phase, critical and recovery phase.

i.Febrile Phase

-high grade fever ;develop suddenly

-lasts 2-7 days

-facial flushing

-skin erythema

-generalised body ache

-myalgia/arlthralgia

-headache

-some will get sorethroat,conjunctival infection and injected pharynx

-ANOREXIA,NAUSEA AND VORMITING ARE COMMON

ii.Critical Phase

-usually between 3rd to 5th day of fever,may go up to 7th day

-last about 24-48 hours

-plasma leakage happen in this phase

-pulse rates increase and pulse pressure narrow

-abdominal pain with persistent vormiting

-in some case ;restlessness

-altered conscious level

-clinical fluid accumulation

-mucosal bleed or liver enlargement > 2cm

-in this phase, patient are in possibility of rapid progression to shock

-thrombocytopaenia and haemoconcentration ( raised of Haemotocrit and decrease level of platlet )

-temperature maybe normal or decrease in this phase

iii.Recovery Phase

-happen when plasma leakage stops, reabsorption of extravascular fluid

-patient generally well being improves,appetite returns, gastrointestinal symptoms abate and haemodynamic status stabilises

-some has classical rash of ' isles of white in the sea of red '.

-maybe generalised pruritus

-HCT level stabilises drops due to haemodilution following reabsorption of extravascular fluid

-recovery of platlet count and white cell count

What is important in dengue fever is about the plasma leakage. This is because this condition can lead the illness to one stage that are highly dangerous : DSS/DHF ( DENGUE SHOCK SYNDROME/DENGUE HAEMORHAGIC FEVER )

There are few clinical manifestations that can lead to leakage of plasma

a. skin - coolness, pallor, delayed capillary refill time

b. Renal system - reducing urine output

c. Cardiovascular system - raised diastolic blood pressure and a narrowing of pulse pressure

d. Gastrointestinal system - vormiting and abdominal pain

e. Central nervous system - lethargy, restlesness, apprehension, reduced level of consciousness

f. Respiratory - tachypnoea ;respiratory rate >20/min

TOURNIQUET TEST

In DHF grade 1, a positive tourniquet test serves as the only indicator haemorrhagic tendecy.

How to perfom tourniquet test???

-Inflate the blood pressure cuff on the upper arm to a point midway between systolic and diastolic pressures for 5 minutes

-a positive test is when 20 OR MORE PETECHIAE per 2.5 cm ( 1 inch ) square are observed.
-The tourniquet test may be helpful in the early febrile phase ( less than 3 days ) in differentiating dengue from other febrile illnesses.

-avoid are better than cure-