A 24-year-old woman presents to her primary care physician for evaluation of a three-week history of fatigue, headache, and abdominal pain. She also endorses feeling “foggy” and more clumsy than usual. Her medications include a daily vitamin D supplement and a combined oral contraceptive pill. Physical examination is significant for subconjunctival pallor, and labs indicate anemia. Peripheral blood smear shows erythrocytes with basophilic stippling.
Which of the following additional features is most likely to be present in this patient’s history?
- A) Abetalipoproteinemia
- B) History of splenectomy
- C) Recent travel to Africa
- D) Works at a battery recycling plant
- E) Vegan diet
D) Works at a battery recycling plant
This occupation places the patient at risk for lead poisoning, which manifests as basophilic stippling on peripheral blood smear. Lead inhibits two enzymes in heme synthesis (aminolevulinic acid dehydratase and ferrochelatase) and inhibits rRNA degradation, which is visualized as basophilic stippling. Other manifestations of lead poisoning include encephalopathy, peripheral neuropathy (e.g., wrist/foot drop), and lead lines on the gingiva at the bases of teeth.
Answer choice A: Abetalipoprotinemia, is incorrect. This autosomal recessive condition is the result of a microsomal transfer protein (MTP) mutation and is more likely to produce acanthocytes (spur cells) on blood smear. This disease leads to the absence of chylomicrons, very low-density lipoportein (VLDL), and low-density lipoprotein (LDL), resulting in fat malabsorption.
Answer choice B: History of splenectomy, is incorrect. Patients with asplenia or splenic dysfunction are more likely to present with Howell-Jolly bodies on peripheral smear. These patients may also have a history of infection with encapsulated organisms.
Answer choice C: Recent travel to Africa, is incorrect. Travel to areas where malaria is endemic can lead to parasite infection, and blood smear is more likely to show intraerythrocytic parasite inclusions. Depending on the species, blood smear may show trophozoite rings (P. malariae), schuffner stippling (P. vivax/ovale), or crescent gametocytes (P. falciparum).
Answer choice E: Vegan diet, is incorrect. A strict vegan diet without supplementation can lead to vitamin B12 deficiency. This would result in a macrocytic anemia and may present with neurologic symptoms such as numbness or tingling in the hands and feet.
Key Learning Point
Lead poisoning can manifest with fatigue, confusion, and abdominal pain and results in basophilic stippling in erythrocytes on peripheral blood smear.
Dr. Ted O'Connell