Introduction: The state of Yucatan, in Mexico, is an endemic area for dengue. During 2015, there was an unexpected increase in the number dengue fever cases. Objective: To describe and analyse the clinical presentation, progress, and management of a case of dengue infection with non-specific clinical manifestations in an infant, associated to a dengue shock syndrome. Case report: One monthold infant admitted to hospital with a generalised rash and a history of being bitten by an insect. Anaphylaxis was diagnosed based on clinical manifestations and anamnesis. The infant developed hypotension, tachycardia, anaemia, and respiratory distress. He was transferred to the intensive care unit, dying on the fifth day. He tested positive to dengue virus in the PCR test and for IgG antibodies using Elisa. The cause of death was a dengue shock syndrome. Conclusions: Dengue fever in young infants may be afebrile, so it is important to suspect them appropriately in the presence of a generalised rash, tachycardia, and hypotension, in order to avoid the deadly consequences of dengue shock.