added nbme12 tag b/c directly answers the Q:
An 82-year-old woman who resides in a skilled nursing care facility is transferred to the hospital because of a 2-day history of fever and cellulitis of the left side of her face. She is hemiparetic, aphasic, and unable to swallow. She is fed through a gastrostomy tube. Her temperature is 39.1°C (102.4°F), pulse is 84/min,respirations are 24/min, and blood pressure is 112/72 mm Hg. A firm, exquisitely tender mass is palpated from the left cheek to the angle of the mandible; this area is also erythematous and edematous. The mouth is dry. Her leukocyte count is 28,000/mm (78% segmented neutrophils,
18% bands, and 4% lymphocytes), and serum glucose concentration is 168 mg/dL. What is the cause of the patient's fever?
Answer: Acute suppurative parotitis
Explanation: Risk factors for the development of parotitis include being elderly, dehydration, poor dentition, lack of salivary flow (in setting of poor or absent chewing or oral intake), or debilitation.