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A 30-year old woman is being evaluated for a cramping abdominal pain that has been occurring for the past 6 months. She has intermittent vomiting, constipation, difficulty urinating, and leg weakness. She presents again with similar symptoms in the emergency department. She has no other medical issues or allergies and does not take any medications. Her temperature is 37 C (98.6 F). Examination is unremarkable and she does not have any abdominal rebound tenderness. An extensive evaluation is initiated and findings include a normal white blood cell count, urinalysis, liver function tests, amylase, lipase, and beta-hCG. A prior evaluation has showed normal abdominal imaging, endoscopy and angiography. Urinary porphobilinogen excretion is elevated. Which of the following is the appropriate management?
A. Aspirin administration
B. Intravenous heme administration
C. Intravenous narcotic analgesics administration
D. Pyridoxine administration
E. Sunlight avoidance
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hold on , i need to post the lab result here
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bicarb....24
BUN...18
CL...103
creatining...1.0
glucose....103
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i think lab is not helpful in this q
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B. Intravenous heme administration
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k....3.9
na...135
HCT...30
platelete....128,000
wbc....3,500
mcv...122
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correct answer is B. This patient has a porphyria--an inherited or acquired disorder of heme biosynthesis. Acute intermittent porphyria (AIP) is caused by a deficiency of HMB synthase. Heterozygotes for the condition are prone to recurrent abdominal pain. The test of choice is increased urinary porphobilinogen level. Heme therapy causes feedback inhibition of early heme biosynthesis and reduces attacks.
Aspirin administration may cause some resolution in the pain, but will not treat the underlying condition in this patient (choice A).
Narcotics may ameliorate some of the pain but will not prevent recurrent attacks (choice C).
The severe anemia may respond to pyridoxine supplementation (choice D).
Porphyria cutanea tarda (PCT) is the most common porphyria and involves cutaneous photosensitivity. Neurologic manifestations are not seen (choice E).
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The correct answer is E. This patient has the signs and symptoms of vitamin B12 deficiency and may have pernicious anemia, hinted at by the vitiligo and atrophic tongue. Although hypersegmented neutrophils, neurologic findings, and macrocytic anemia are practically pathognomonic for vitamin B12 deficiency, it should be confirmed. Low normal range values of vitamin B12 deficiency and normal blood smears (without anemia or hypersegmented neutrophils) can occur in up to 25% of patients, necessitating further testing. If vitamin B12 levels are borderline normal, vitamin B12 deficiency can be confirmed by documenting elevations in methylmalonic acid and homocysteine. Serum methylmalonic acid and homocysteine levels are elevated in vitamin B12 deficiency, while elevated levels of homocysteine but not methylmalonic acid are seen in folate deficiency. These tests measure tissue vitamin stores and may demonstrate a deficiency even when the more traditional but less reliable folate and cobalamin levels are borderline or even normal. Patients (particularly older patients) without anemia and with normal serum vitamin B12 levels but elevated levels of serum methylmalonic acid may develop neuropsychiatric abnormalities.
Bone marrow biopsy (choice A) is invasive and painful and is not indicated. This patient™s mild pancytopenia likely is caused by her vitamin B12 deficiency. More information is unlikely to be found on a bone marrow stain.
An empiric trial of therapy (choice B) is a poor choice for two reasons. First, if this patient has pernicious anemia, a common cause of vitamin B12 deficiency, oral vitamin B12 will not be absorbed. Second, it takes months to see improvement from this therapy, making it a difficult diagnostic test that will delay treatment if the wrong diagnosis is suspected.
Folate deficiency, checked with a folate level (choice C), is unlikely, given the neurologic findings in this patient. Folate deficiency is a cause of megaloblastic anemia. Vitamin B12 deficiency needs to be ruled out, as folate will cure the anemia, but allow the neurologic disease to progress unchecked.
An iron panel (choice D) is not useful in this patient. Iron deficiency anemia is microcytic and is extremely unlikely in a patient with macrocytosis.
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sorry the answer is E..., the answer to no 1 was not deleted so it pasted again
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