Final answer:
An unexpected symptom in the progression of RSV bronchiolitis in infants is a pustular rash, which is more characteristic of other types of infections. Typical symptoms of RSV in infants include fever, cough, and respiratory distress, with supportive care as the primary treatment.
Step-by-step explanation:
A symptom that is unexpected in the progression of bronchiolitis caused by respiratory syncytial virus (RSV) infection in a 7-month-old client would be a pustular rash of lesions that burst and form crusty scabs. Common symptoms include fever, cough, congestion, and in severe cases, respiratory distress, but a pustular rash would be atypical for RSV infections and could indicate a different infection, such as chickenpox or smallpox.
RSV is most likely to cause severe illness in infants and young children, potentially leading to life-threatening respiratory issues, unlike adults where it typically causes mild cold-like symptoms. While there are no specific antiviral therapies or vaccines for viral pneumonia caused by RSV, treatment generally involves supportive care such as oxygen therapy, hydration, and in some cases, hospitalization to manage symptoms and prevent complications.