Diabetes mellitus Quiz: Ace Your Exams

A 55-year-old man comes to the emergency department with fevers and a cough for the past week. The fever is intermittent and associated with a dull headache. The cough is non-productive, and the patient denies sore throat, nasal congestion, shortness of breath, or chest pain. He has a history of type 2 diabetes mellitus diagnosed 5 years ago. Initially, the patient was prescribed oral antihyperglycemics, but he switched to herbal remedies after one month because of side effects. The patient has never smoked cigarettes. He is employed as a groundskeeper at a local country club. The patient’s temperature is 36.4°C (97.5°F), pulse is 100/min, respirations are 20/min, and blood pressure is 120/70 mmHg. Physical examination shows occasional coarse left-sided crackles on lung auscultation. Neurologic and skin examinations are normal. Serum laboratory studies show the following:  

Laboratory value	Result	Reference Range
White blood cells	28,000 /mm3	4,500-11,000/mm3
Creatinine	2.3 mg/dL	0.6-1.2 mg/dL
Glucose	374 mg/dL	70-110 mg/dL
Bicarbonate	19 mEq/L	22-28 mEq/L
Ketones	Positive	Negative

   
Chest X-ray shows homogenous opacities in the left upper lobe. Nasal endoscopy shows extensive inflammation of the left nasal cavity and maxillary sinus. Sputum microscopy shows the following:


Reproduced from: Wikimedia Commons

Which of the following is the most likely diagnosis?