Infectious mononucleosis complicated by lingual tonsillitis. Although upper airway obstruction and superimposed infection are well-known complications of infectious mononucleosis, lingual tonsillitis in this context has not been mentioned in the literature. We describe a case of acute bacterial lingual tonsillitis with airway obstruction complicating infectious mononucleosis. The role of the base of tongue region in the pathophysiology of infectious mononucleosis is discussed. 