emphysematous urinary tract infections ( utis ) are infections associated with gas formation that may present as cystitis , pyelitis , or pyelonephritis .
uncontrolled diabetes mellitus is a major risk factor for this type of infection , as it provides a favorable microenvironment for the gas forming organisms to grow , .
we present a case of emphysematous pyelitis caused by candida tropicalis with good outcome due to early recognition and treatment .
a 49 year old man presented to the emergency department on day 0 with a two week history of intermittent right flank pain associated with nausea and vomiting .
his medical history included diabetes mellitus , hepatitis c , schizophrenia , and intravenous ( iv ) substance abuse .
his home medications included nateglinide , metformin , clonazepam , risperidone , fluoxetine , trazodone , and benztropine . on initial physical examination
, he had a fever of 38.7  c ( 101.6  f ) , blood pressure of 150/80  mm hg with a heart rate of 80 beats per minute , and right costovertebral angle tenderness , with otherwise unremarkable findings .
the initial laboratory workup showed a hyperglycemia of 496  mg / dl , but no leukocytosis or abnormal renal functions .
urine analysis was positive for white and red blood cells with negative nitrite and leukocyte esterase .
computed tomography ( ct ) scan showed free air within both collecting systems and urinary bladder with no signs of air inside the renal parenchyma .
iv ceftriaxone and insulin therapy were started , foley catheter was placed , and urine cytology was sent to the lab . on further questioning , the patient reported passing friable pinkish material with his urine ,  like chicken fat  he described . on day 1 , the patient 's fever persisted and antibiotic were switched to piperacillin - tazobactam . on day 2 ,
the hemoglobin a1c was 14.9% and a repeat ct scan with iv contrast was still suggestive of emphysematous pyelitis ( fig .
enterovesical fistula was ruled out by an oral - activated charcoal test . on day 4 ,
the urine culture came back positive for c. tropicalis ( > 100,000  cfu / ml ) identified by vitek ms system .
iv fluconazole 400  mg was started followed by 200  mg daily . on day 5 ,
a final ct scan on day 6 showed resolution of the emphysematous pyelitis with some remaining mild parenchymal edema and he remained afebrile .
the patient was discharged on oral fluconazole 200  mg to complete two weeks of therapy .
emphysematous infections are usually caused by gas - producing organisms ; mainly bacterial like escherichia coli , klebsiella pneumoniae , proteus mirabilis and pseudomonas aeruginosa .
fungal etiology has rarely been reported , but in this case the infection was caused by c. tropicalis 
 .
the method of choice for diagnosis and follow up of emphysematous uti is ct scan .
class 1 , is when gas is only limited to the collecting system . in class 2
, gas is found in the renal parenchyma without extension to the extrarenal space . in class
3a , gas extends to the perinephric space and in class 3b , it extends to the pararenal space . in class 4 , there is bilateral renal involvement or emphysematous pyelonephritis of a solitary kidney , .
the new approach in treating emphysematous utis is the use of systemic antibiotics , together with percutaneous drainage of gas and purulent material .
if urinary tract obstruction is present , it must be relieved as well , , . in this case , the patient was class 1 and was successfully managed by systemic antibiotic and antifungal therapy , together with decompression of the urinary system by foley catheter . no invasive intervention was required .
he responded well to treatment , mainly due to early diagnosis , sequential radiological assessment , and the fact that it was pyelitis rather than pyelonephritis .
 a patient with uncontrolled diabetes mellitus presented with fever and flank pain . 
 a computed tomography scan showed free air within both collecting systems . 
 a diagnosis of emphysematous pyelitis was made after other alternative diagnoses were ruled out . 
 urine culture grew candida tropicalis . 
 the emphysematous pyelitis resolved with conservative management using antifungal therapy . 
Introduction
Case
Discussion
Conflict of interest