In dengue hemorrhagic fever, which of the following is a critical sign?

In dengue hemorrhagic fever, bleeding symptoms are critical indicators of the severity of the disease. Bleeding from the gums signifies the potential progression of the illness into a more severe form, which can lead to other complications such as shock and multi-organ failure. This symptom indicates a breakdown of blood vessel integrity and an increased risk of internal bleeding, which is a hallmark of dengue hemorrhagic fever.

The presence of bleeding from the gums reflects the overall state of the patient's coagulation status and can alert healthcare providers to the need for close monitoring and intervention. Timely recognition of this critical sign can lead to appropriate management strategies to mitigate complications associated with severe dengue.

Other signs listed, such as persistent cough, abdominal swelling, or excessive sweating, do not carry the same level of urgency concerning the immediate risks associated with dengue hemorrhagic fever. They may indicate other conditions or complications but lack the direct association with severe bleeding and the potential for mortality that is characteristic of this serious manifestation of dengue.