Which sign or symptom is most indicative of a systemic reaction after ingesting poison?

Tachycardia and hypotension are critical signs that indicate a systemic reaction to poisoning. When a person ingests a toxic substance, it can lead to a range of physiological responses, including cardiovascular disturbances. Tachycardia, or an increased heart rate, occurs as the body attempts to compensate for reduced blood pressure seen in hypotension, or abnormally low blood pressure. This response suggests that the body is in a state of distress and is struggling to maintain adequate blood flow and oxygen delivery to vital organs.

In contrast, other symptoms, such as nausea and vomiting, while distressing, are more common in localized reactions or mild toxicity rather than indicating a systemic response. Burns around the mouth usually signify acute exposure to caustic substances and do not necessarily reflect a systemic reaction. Similarly, difficulty swallowing primarily points to localized irritation or injury in the oropharyngeal area rather than a wider systemic effect. Thus, the presence of tachycardia and hypotension is a clear indicator that the body is experiencing a systemic reaction following the ingestion of poison.