An 18-month-old child is brought to the physician by her parents because of a sore throat, difficulty breathing, and a barking cough for the past day. On physical examination the toddler is found to have some respiratory stridor and a runny nose but is not in acute distress. The rest of the examination is unremarkable. Which of the following is the most appropriate treatment?
(A) Amantadine
(B) Bronchoalveolar lavage
© emergency department admittance
(D) Penicillin
(E) Supportive therapy