5-65
Patient Education
General: Do not expose others to infected secretions. Cover mouth if cough or sneeze. Wash hands
frequently.
Diet: Regular, but take extra fluids
Medications: Acetaminophen for discomfort or fever.
Prevention and Hygiene: Vaccination against types 4 and 7 in military populations previously reduced
outbreaks of acute respiratory disease among recruits. However, susceptibility has returned after cessation
of routine vaccination.
Follow-up Actions
Evacuation/Consultation Criteria: Evacuate any unstable patients. Consult primary care physician or
pulmonologist as needed.
ID: Dengue Fever
LTC Niranjan Kanesa-thasan, MC, USAIntroduction: Dengue fever is a mosquito-borne viral infection especially prevalent in dense, urban centers
in the tropics and subtropics. Most dengue infections are asymptomatic, but it may present as an acute,
undifferentiated fever with headache, and myalgias. Classically, excruciating pains in the back, muscles,
and joints (‘breakbone fever’) occur in adults. Most patients recovery fully, but some individuals with
previous exposure to dengue will develop a more severe form called dengue hemorrhagic fever (DHF), with
hypotension and bleeding, which if unchecked will progress to shock and death. Geographic Association:
Wet tropical and subtropical areas in most of Latin America, Asia and the Pacific Islands. Seasonal
Variation: Outbreaks typically follow rainy seasons in tropical regions, which produce increased densities of
the mosquito vector. However, year-round transmission is found in endemic regions. Risk Factors: Travel to
dengue-endemic area, with exposure to mosquito bites, is the principal risk factor.
Subjective: Symptoms
Sudden onset of fever, headache, and myalgias after a brief (1-2 days) prodrome of sore throat, nausea,
and abdominal pain. Other symptoms: chills, malaise, prostration (similar to severe flu), retroorbital pain,
photophobia. DHF: Rash, bleeding, mental status changes.
Focused History: What symptom bothers you the most? (severe headache, muscle pain, retroorbital pain,
photophobia are typical) When did you first feel sick? (Typically, patient recalls exact time of onset of fever,
headache, and prostration, usually within past several days.) Have you traveled overseas within the past 2
weeks? (look for travel to endemic areas [see above] to establish exposure)
Objective: Signs
Using Basic Tools: Vitals: Cyclical fevers to 104°F over days (‘saddle-back fever’); DHF: Bradycardia,
hypotension.
Inspection: flushing with conjunctival injection; prominent maculopapular, blanching rash over trunk and
extremities, sparing palms and soles; no petechiae or purpura except with DHF (see Note below).
Palpation: Cervical lymphadenopathy, hepatomegaly; diffuse, abdominal tenderness without guarding
Using Advanced Tools: Lab: Neutropenia on WBC (<1.5 x 10^6 /mm^3 ); blood smears x 3 to rule out malaria;
serial hematocrit and platelet counts (hematocrit rising to >50%, decreasing platelet count to <100,000/mm^3
suggest DHF).
DHF: Perform a tourniquet test if DHF is suspected: inflate blood pressure cuff to a point midway between
systolic and diastolic blood pressures, maintain for 5 minutes, release pressure and wait 2 minutes or more,
then count the number of petechiae that appear in a quarter-sized area (2.5 cm diameter) on the skin distal to
the cuff. More than 10 petechiae indicate vascular or platelet disorder and suggest DHF.
Assessment:
Differential Diagnosis