The state of Yucatan, in Mexico, is an endemic area for dengue. During 2015, there was an unpredicted increase in the number of expected cases of dengue fever. 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 which resulted in a dengue shock syndrome. METHODS One month old infant admitted to hospital with a generalised rash and a history of being bitten by an insect. He was diagnosed with anaphylaxis based on clinical manifestations and anamnesis. While in hospital, he developed hypotension, tachycardia, anaemia, and respiratory distress. He was transferred to the intensive care unit, but died on the fifth day. He tested positive to dengue virus in the PCR test and for IgG antibodies using Elisa. The basic cause of death was dengue shock syndrome. CONCLUSIONS Dengue fever in young infant infections 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.