Which of the following is a symptom of serotonin syndrome?

Serotonin syndrome is a potentially life-threatening condition resulting from an excess of serotonin in the central nervous system, often due to medication interactions or overdose of serotoninergic drugs. The hallmark symptoms of serotonin syndrome typically include autonomic instability, altered mental status, and neuromuscular symptoms.

The presence of fevers and muscle rigidity is particularly significant, as these symptoms indicate hyperreflexia and increased muscle tone, which are commonly associated with serotonin syndrome. The elevated body temperature can occur due to increased metabolic activity and muscle rigors that are characteristic of excessive serotonergic activity in the nervous system.

While other options such as nausea and vomiting can occur in serotonin syndrome, they are not specific indicators of the condition, making fevers and muscle rigidity a more definitive symptom indicative of the syndrome's severity and the potential for complications. Overall, the combination of fevers and muscle rigidity serves as important clinical indicators that prompt healthcare providers to investigate potential serotonin toxicity.