–Affected patients typically become rapidly and acutely ill, with the sudden onset of a sore throat, a high fever, and
tachypnea. Labored breathing may lead to high blood carbon dioxide levels and low oxygen levels, possibly causing
agitation and confusion followed by lethargy. Patients may drool because of difficulty swallowing saliva, and often will
lean forward when sitting and tilt the head backward; a posture that eases breathing by increasing the diameter of the
airway