Gastroenterology Today Summer 2021

CASE REPORT
of toxicity. Clinical manifestations of lead toxicity are varied and can
be non-specific. Acute toxicity often manifests as abdominal pain,
constipation, body pains, decreased libido, headaches, memory
problems and irritability. Chronic exposure can produce anaemia,
reduced neuro-cognitive function, nephropathy, tremor, hearing loss
and hypertension 2 .
In the paediatric population lead toxicity risks significant and
irreversible neurodevelopmental damage and should be investigated
in any child presenting with an unexplained alteration in mental
state and behavioral changes in the presence of risk factors for lead
exposure 3 .
An elevated blood lead level reflects recent exogenous exposure as
well as release of endogenous lead from bone and soft tissue stores.
Toxicity is thought to develop due to lead competing with calcium in
several biological processes, inhibiting enzymes, and altering the
permeability of the blood brain barrier.
The mainstay of management is the separation of the patient from
the source of the lead exposure. In patient with very elevated lead
levels (>50 mcg/dL) or symptoms of acute toxicity chelation therapy
can be considered under specialist guidance 4,5 . The two most
commonly used chelating agents are DMSA (2,3-dimercaptosuccinic
acid) or EDTA (calcium disodium ethylenediaminetetraacetic acid).
Chelation should not be undertaken unless exposure to lead has
been curtailed, as in the presence of ongoing lead exposure,
chelation may lead to enhanced absorption of lead and therefore
worsening toxicity.
Regular and long-term monitoring of lead levels is required until
normal levels are achieved, as lead can be stored in bone for several
decades. Patients with established sequelae of lead toxicity such as
cardiovascular disease, cognitive dysfunction and renal failure are
unlikely to see reversibility of their symptoms over time even with
chelation therapy.
Conclusion
Lead toxicity is an uncommon yet important differential in patients
presenting with persistent abdominal pain. Prompt diagnosis and
subsequent treatment is imperative in negating the potentially long-term
damaging effects of lead on multiple organ systems. In these patients,
a through social history is the most crucial, but often overlooked, step in
reaching the diagnosis.
References
1. J. Route Reigart, British Medical Journal Best Practice
Guidelines; Approach to Lead Toxicity. Updated 17th April 2021.
https://bestpractice.bmj.com/topics/en-gb/755/diagnosisapproach#referencePop27
2. National Toxicology Program. Health effects of low-level lead
evaluation. Research Triangle Park, NC: US Department of Health
and Human Services; 2012. http://ntp.niehs.nih.gov/pubhealth/hat/
noms/lead/index.html
3. D. A. Gildow, Lead Toxicity, Occupational Medicine 2004;54:76–81
DOI: 10.1093/occmed/kqh019
4. Lin JL, Ho HH, Yu CC. Chelation therapy for patients with
elevated body lead burden and progressive renal insufficiency. A
randomized, controlled trial. Ann Intern Med 1999; 130:7.
5. Association of Occupational and Environmental Clinics. Medical
management guidelines for lead-exposed adults. April 2007. http://
www.aoec.org
6. Centres for Disease Control (CDC) and Prevention. Adult blood lead
epidemiology and surveillance (ABLES). http://www.cdc.gov/niosh/
topics/ables/description.html
Table 1: Risk Factors for Lead Exposure 1
Age
Pica syndrome
Housing environment
Occupation
Recreational activities
Traditional / herbal medicines
Children between the ages of 9-36 months are at the most risk of ingesting lead-containing substances in
their environment.
Compulsive ingestion of material with no nutritional value. Most commonly seen in children and pregnant
women.
Older homes (built before 1970) may have lead piping or lead paint.
Any job that involves handling material that may include lead, especially construction and decorating. The
risk is increased if the job entails sanding down walls or removing paint which generates a fine dust of lead
particles that are easily inhaled and ingested.
Including painting, figurine or jewelry making and stained glass making.
Any herbal remedy may contain lead. Most common sources are Ba- baw-san (traditional Chinese remedy
for colic), Daw Tway (used in Thailand and Burma as a digestive aid), Greta (traditional Hispanic remedy
for digestion or used during teething) and Ghasard (Indian folk medicine used as a tonic)
GASTROENTEROLOGY TODAY - SUMMER 2021
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