One the one hand, acute cholangitis is a true medical emergency, with the patient being septic, toxic and shock, i.e. the pentad of Raynolds should make you think more of cholangitis than cholecystitis. Of course, this doesn't mean that cholocystitis may not present in this way, but in a pt presenting very ill (and for the shake of USMLE) always suspect cholangitis.
One the other hand, suspect this entity in cases that suggest a possibility of disturbance of the normal flow of bile from the biliary tree though the ampulla to the duodenum. Conditions such as underlying pancreatic Ca, history of ERCP, ampullary stenting or alteration of the anatomy of the region in any way are highly suggestive. Again, gallstones constitute the most frequent underlying cause, but the abovementioned culprits are red alerts for cholangitis.
The definitive differential can be given only by means of imaging, but those clinical hints may prove helpful when in doubt on no imaging option is given in the questions stem or the available answers.
One the other hand, suspect this entity in cases that suggest a possibility of disturbance of the normal flow of bile from the biliary tree though the ampulla to the duodenum. Conditions such as underlying pancreatic Ca, history of ERCP, ampullary stenting or alteration of the anatomy of the region in any way are highly suggestive. Again, gallstones constitute the most frequent underlying cause, but the abovementioned culprits are red alerts for cholangitis.
The definitive differential can be given only by means of imaging, but those clinical hints may prove helpful when in doubt on no imaging option is given in the questions stem or the available answers.
