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OVERVIEW
This page is dedicated to organizing various examples of standardized exam questions whose answer is lead poisoning. While this may seem a odd practice, it is useful to see multiple examples of how lead poisoning will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a tradition question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a disease is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each condition has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for lead poisoning.
- Lead exposures: lead paint (especially homes/buildings that have very old paint), ammunition, batteries, construction
- GI symptoms: abdominal pain, constipation, anorexia
- Neurological symptoms: cognitive defects, peripheral neuropathy
- Hematologic anemia: microcytic/hypochromic in nature
- Basophilic stippling: frequency seen on peripheral blood smear caused by aggregation of residual ribosomes.
- Serum findings:
- Elevated venous lead level
- Elevated serum zinc protoporphyrin level
QUESTION EXAMPLES
Question # 1
A 3 year old boy presents with the clinic with increasing anorexia, apathy, irritability, decreased play activity, poor coordination, and sporadic vomiting for the past 4 weeks. A physical exam is unremarkable. Lab studies show hypochromic, microcytic anemia. What is a possible diagnosis?
TESTABLE FACTS ABOUT THIS TOPIC (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying topic. Often there are specific testable facts regarding some aspect of the topic’s pathophysiology/management/clinical implications that are commonly asked. Some of these are listed below:
- Cause: accumulation of lead in the body
- Consequence of accumulated lead:
- Inhibition of nucelotidase: causes abnormal degradation of ribosomal RNA (causing the basophilic stippling)
- Inhibition of aminolevulinate dehydratase (ALA-dehydratase): this causes the reduced incorporation of iron into heme. Net effect is deceased hemoglobin synthesis.
Page Updated: 11.06.2016