What is one of the primary symptoms you would expect in a person exposed to smallpox?

Blistering lesions are indeed one of the primary symptoms of smallpox. This viral infection is characterized by a distinct and progressive rash that evolves into blister-like lesions. Initially, smallpox manifests with fever and malaise, followed by the appearance of the rash, which typically begins on the face and can spread to other parts of the body. The lesions are often painful and form pus-filled blisters that eventually crust over and fall off, leaving scarring.

The other symptoms listed, while they may occur with various infections or conditions, are not hallmark signs of smallpox. For instance, watery eyes, vomiting, and severe headache can be associated with multiple diseases but do not specifically define smallpox. The striking and unique presentation of blistering lesions is what helps differentiate smallpox from other illnesses, making it a critical symptom in identifying and diagnosing the condition.