Dengue shock syndrome (DSS) represents the severe end of the dengue spectrum, classified by the World Health Organization as severe dengue with significant plasma leakage progressing to shock. DSS is most commonly precipitated by secondary heterotypic infection with a different DENV serotype (1-4) through antibody-dependent enhancement (ADE), where preexisting non-neutralizing antibodies facilitate viral entry into Fc receptor-bearing monocytes and macrophages, amplifying viremia and proinflammatory cytokines. Adults can develop shock with their first infection, particularly when comorbidities such as diabetes, obesity, or cardiovascular disease are present.
The disease evolves through three phases: febrile (days 1-3) with fever, rash, myalgia, and headache; critical (days 4-7) when defervescence coincides with plasma leakage, increasing hematocrit, decreasing platelets, and risk of shock or hemorrhage; and recovery (days 7-10) with reabsorption of extravasated fluid and gradual normalization. Warning signs heralding deterioration include severe abdominal pain, persistent vomiting, mucosal bleeding, lethargy, hepatomegaly more than 2 cm, hematocrit rise concurrent with rapid platelet drop, and pleural effusion or ascites. Shock manifests as narrowed pulse pressure (less than 20 mmHg), tachycardia, cool clammy extremities, prolonged capillary refill, and hypotension; profound shock with multiorgan dysfunction, severe bleeding, or AST/ALT elevations greater than 1000 U/L defines compensated to uncompensated shock.
Management emphasizes meticulous fluid resuscitation balancing the dual risks of hypovolemia and fluid overload during reabsorption. Initial isotonic crystalloid bolus 5-10 mL/kg over 1 hour for compensated shock, escalating to 10-20 mL/kg for uncompensated shock, with reassessment of hematocrit, vital signs, and urine output every 15-30 minutes. Colloid (5% albumin or hydroxyethyl starch) is reserved for refractory shock. Blood and blood product transfusion (packed red cells, platelets, fresh frozen plasma) targets bleeding and severe coagulopathy rather than thrombocytopenia per se. Non-steroidal anti-inflammatory drugs are avoided due to bleeding risk, and aspirin is contraindicated. Most patients recover within 7-10 days with timely supportive care; mortality approaches less than 1% in well-resourced settings but exceeds 20% in delayed presentation. Prevention relies on vector control and the dengue vaccine (Qdenga, CYD-TDV) in seropositive individuals.