06-29-2012, 03:39 PM
Answer.C
Reddish discolration of urine with a negative dipstick for blood suggests that this red color is not from either a pigment globin ( hemoglobin or myoglobin) or a Red blood cell ( Hematuria). Such red colored urine with negative dipstick can be seen with drugs such as Rifampin, foods such as beets and substances like porpyrins in urine.
This patient also has sensory as well as motor neuropathy in his lower extremities, a typical manifestation of Acute intermittent porpyria attacks. The presence of peripheral neuropathy in patients with history of recurrent abdominal pains should raise the suspicion of Acute Intermittent Porphyria ( AIP). This patient had several severe abdominal pain episodes which were misdaiagnosed as appendicitis and he even underwent a futile laparotomy. Patients are pain free between the attacks. Fasting and drugs like phenobarbital, alcohol can precipitate AIP attacks. Unlike other porphyrias, rash is not typically seen in AIP.
A. is not the answer because dipstick would be positive for blood in rhabdomyolyisis
B. is not the answer because dipstick would be positive in hemoglobinuria
D. is not the answer since the diagnosis of reddish urine here is not in favor of myoglobinuria.
E. a negative dipstick and negative microscopic urinalysis rules out gross hematuria as a cause of this red urine
F. Negative dipstick for blood, negative urine microscopy and absence of RBC casts rule out glomerulonephritis as a cause of this patient’s red urine
Reddish discolration of urine with a negative dipstick for blood suggests that this red color is not from either a pigment globin ( hemoglobin or myoglobin) or a Red blood cell ( Hematuria). Such red colored urine with negative dipstick can be seen with drugs such as Rifampin, foods such as beets and substances like porpyrins in urine.
This patient also has sensory as well as motor neuropathy in his lower extremities, a typical manifestation of Acute intermittent porpyria attacks. The presence of peripheral neuropathy in patients with history of recurrent abdominal pains should raise the suspicion of Acute Intermittent Porphyria ( AIP). This patient had several severe abdominal pain episodes which were misdaiagnosed as appendicitis and he even underwent a futile laparotomy. Patients are pain free between the attacks. Fasting and drugs like phenobarbital, alcohol can precipitate AIP attacks. Unlike other porphyrias, rash is not typically seen in AIP.
A. is not the answer because dipstick would be positive for blood in rhabdomyolyisis
B. is not the answer because dipstick would be positive in hemoglobinuria
D. is not the answer since the diagnosis of reddish urine here is not in favor of myoglobinuria.
E. a negative dipstick and negative microscopic urinalysis rules out gross hematuria as a cause of this red urine
F. Negative dipstick for blood, negative urine microscopy and absence of RBC casts rule out glomerulonephritis as a cause of this patient’s red urine