The following symptoms and complaints may indicate dengue fever:
Symptoms of dengue fever range from mild flu-like symptoms to serious complications such as hemorrhages (bleeding) or severe shock syndrome. Symptoms of classic dengue fever (DF).
- High fever (up to 40 °C, 48-96 hours) with a brief drop in fever on day 3-4 (often, but not always, biphasic/”proceeding in two phases”).
- Erythema (extensive reddening of the skin), especially on the face and chest, which can be pushed away; often with white dermographism (skin reaction visible a few seconds to minutes after moderately strong mechanical irritation (e.g., by a wooden spatula))
- Exanthema (skin rash), maculopapular (patchy and with papules, i.e., vesicles):
- Beginning on the dorsum of the hands and feet and then spreading to the proximal extremities and trunk (truncal), sparing the face [50% of patients have this after transient defever].
- Nappes-claires-like recesses of unaffected skin (“islands of white in a sea of red”) are characteristic.
- Mild bleeding signs (petechiae/punctate skin hemorrhages, bleeding from puncture sites).
- Chills
- Headache (frontal and retroorbital (“behind the eye socket”) headache/retrobulbar pain).
- Conjunctivitis (conjunctivitis)
- Photophobia (photophobia)
- Back pain
- Myalgia (muscle pain) and arthralgia (joint pain; “bone-crushing aspect”; “breakbone fever”/bone-crushing fever)
- Generalized lymphadenopathy (lymph node enlargement) (esp. nuchal/in the neck region).
- Splenomegaly (splenomegaly).
- Conjunctivitis (conjunctivitis)
- Bradycardia – too slow heartbeat: < 60 beats per minute.
- Hypotension – low blood pressure
- Transaminase increase – increase in liver enzymes [moderately increased].
- Thrombocytopenia – decrease in platelets (thrombocytes) in the blood.
- Lymphopenia – decrease in lymphocytes (white blood cells, which are divided into T and B lymphocytes) in the blood.
The convalescence is usually several weeks. Symptoms of mild atypical dengue fever.
In rare cases, hemorrhages (bleeding) and shock can occur as complications already in a first infection – or in a second infection (there are 4 dengue serotypes). Symptoms of dengue hemorrhagic fever (DHS).
- Rapid rise in fever
- Headache
- Nausea / vomiting
- Dyspnea (shortness of breath)
- Petechiae – punctate bleeding of the skin.
- Purpura – small-spot capillary bleeding in the skin, subcutis or mucous membranes (skin hemorrhage).
- Epistaxis (nosebleed)
- Gastrointestinal bleeding (gastrointestinal bleeding).
- Cerebral hemorrhages
- Pneumonia (inflammation of the lungs)
- Thrombocytopenia (reduction in platelets; platelet drop to < 100,000/µl → inpatient admission required).
Symptoms of severe dengue fever.
- Dengue fever +
- Capillary leak syndrome (synonym: Clarkson’s syndrome) – severe disease with generalized edema due to increased permeability of capillary vessels; subsequently, occurrence of severe hypovolemic shock (volume deficiency shock) associated with arterial hypotension (high blood pressure) with hemoconcentration (thickening of blood)
- Dengue shock syndrome (DSS; see below).
- Adult (Acute) Respiratory Distress Syndrome (ARDS) – acute respiratory failure in a previously lung-healthy individual.
- Effusions
- Or severe bleeding
- Or organ dysfunction (e.g., transaminases > 1,000 IU/l; heart failure; impaired consciousness).
Symptoms of dengue shock syndrome (DSS; synonym: dengue vascular permeability syndrome (DVPS)) [2nd phase]
- All DHS criteria (see above) + signs of shock:
- Rapid, weak pulse with small pulse amplitude (< 20 mmHg).
- Or hypotension (low blood pressure)
- Cold sweats
- Restlessness
- Bleeding
- Cardiovascular failure
- Laboratory: increase in hematocrit (proportion of red blood cells (RBCs) in the volume of blood), thrombocytopenia (decreased number (<150,000/µl) of platelets (thrombocytes) in the blood), and hypoproteinemia (decreased concentration of total protein in blood plasma (<60 g/L)).
The lethality (mortality relative to the total number of people suffering from the disease) is up to 44%. Symptoms of convalescence [3rd phase].
- Bradycardia – heart rate <60 beats/min.
- Ventricular extrasystoles (VES) – extra beats from the heart chambers.
- Pruritus (itching)
Warning signs (red flags)
Warning signs of a possible complicated course are:
- Mucosal bleeding
- Abdominal pain (abdominal pain)
- Persistent vomiting
- Hepatomegaly (enlargement of the liver)
- Edema (water retention)
- Proteinuria (increased excretion of protein in the urine).
- Lethargy and restlessness