The signs and symptoms of respiratory syncytial virus infection usually appear four to six days after exposure. RSV usually causes mild cold-like symptoms in adults and older children. A congested or runny nose, a low-grade fever, sneezing, sore throat, headaches, or a dry cough may occur. It is possible for RSV infection to spread to the lower respiratory tract, resulting in pneumonia or bronchiolitis by inflaming the small airways entering the lungs. A severe cough, wheezing, fever, and blueish skin color (cyanosis) may be signs and symptoms. Breathing may also become difficult and rapid. RSV is most severe in infants. When an infant has a severe RSV infection, he or she may experience short, shallow, or rapid breathing. In addition, it can cause irritability, excessive tiredness, poor feeding, and coughing.