doing uworld qbank, i got the following situations:

1. very classic description of a bladder cystitis and they ask us which is the most aprropriate next step in the management...they said because it was so clear the description, we don't need urinary or blood culture and we shoul go with antibiotics(empirical).

2. very classic description of a pyelonephritis several questions later and ask us the same thing: which is the most aprropriate next step in management....here they said is blood/urine culture because ALWAYS we should do culture before going with antibiotics treatment(empirical).

my question is: since cystitis is not so bad, that's why we don't need culture or because it's an error on cystitis management? since on pyelonephritis says that ALWAYS ask for culture before starting antibiotics, this refers only to kidney infection or the rule aply to pretty much every other scenarios in the body? thanks a lot to anybody who can help.