A young adult presents with a sore throat, fever, and malaise along with physical exam findings of posterior cervical lymphadenopathy and splenomegaly. What is the most appropriate instruction for the patient?

The most appropriate instruction for the patient is to avoid strenuous activity and contact sports until advised. This is particularly important in the context of infectious mononucleosis, often caused by Epstein-Barr virus, which is characterized by symptoms such as sore throat, fever, malaise, posterior cervical lymphadenopathy, and splenomegaly.

The reasoning behind this recommendation stems from the risk of splenic rupture which can occur in patients with splenomegaly. Engaging in strenuous activities or contact sports can increase the likelihood of such complications. Therefore, advising the patient to refrain from these activities helps ensure their safety while they recover.

This guidance also allows for appropriate healing and reduces the risk of exacerbating their condition. While other options may appear relevant, they do not address the immediate concern tied to the patient's physical exam findings and the risks associated with their condition effectively.