Department of Pediatrics
Hospital for Sick Children Toronto, Ont.
Previously well, developmentally normal 20-month-old twin girls
presented with weakness, anorexia, a papular rash and increasingly
swollen, red and painful hands and feet of 1 month's duration.They
had no history of fever, conjunctivitis, lymphadenopathyor oral
changes characteristic of Kawasaki disease. The childrenappeared
irritable and unwell and were diaphoretic but afebrile.Both had
tachycardia, and one had an elevated blood pressureof 130/90 mm Hg
(95th percentile for age 108/62 mm Hg). Bothchildren had reduced
muscle power and diminished reflexes. Theirpalms and soles were
erythematous and indurated with desquamation,judged to be acrodynia
().
Figure 2. Photo: Images courtesy Dr.
Michael Weinstein
Mercury toxicity was suspected, and further questionning revealed
that the infants had been given a mercury-containing "teething
powder" from India once or twice a week over the 4 precedingmonths.
The girls' blood mercury levels were 176 and 209 (normally< 18)
µmol/L. Chelation therapy with 2,3-dimercaptosuccinicacid was
administered through nasogastric tubes. Before admissionthe twins
had regressed developmentally and were unable to feedorally, sit or
walk. Over the 8 weeks in hospital they showedsome minor
neurocognitive improvements, but their long-termprognosis is
uncertain.
Mercury exists in inorganic and organic forms. Organic mercuryhas
recently received attention because of the accumulationof
methylmercury in some predatory fish and the use of thimerosalas a
preservative in some vaccines. A type of inorganic mercuryknown as
calomel ("sweet mercury") was once commonly used totreat many
ailments, including yellow fever, typhus and syphilis.Until the
recognition of their toxicity in the 1940s, calomel-basedteething
powders caused a scourge of mercury poisoning called"pink disease"
or acrodynia among infants and children.
Acrodynia is characterized by a dusky pink discolouration, swelling,paresthesia and desquamation of the hands and feet. Symptomsof
catecholamine excess such as sweating and hypertension occurbecause
mercury blocks the degradation pathway of catecholamines.Other
manifestations of mercury toxicity include renal dysfunction,
peripheral neuropathy and neuropsychiatric symptoms (e.g., emotional
lability, memory impairment and insomnia). Although calomel-containingcompounds are banned in North America, they are still used in
other parts of the world such as Southeast Asia, and calomelcan also
be found in various alternative medicine products.
Clinical presentations suggestive of pheochromocytoma (e.g.,
excessive sweating, tachycardia and hypertension) or of Kawasaki
disease but not meeting the full criteria should also prompt
consideration of mercury toxicity. Although rash, oral mucosaand
extremity changes are features of both Kawasaki diseaseand mercury
toxicity, patients with the latter do not have afever. Rash and
extremity changes are not features of pheochromocytoma.The peeling
of the skin on the extremities seen in cases ofKawasaki disease
often occurs 13 weeks after presentation,as opposed to occurring
concurrently with the rash and otherfindings in cases of mercury
poisoning. Mercury poisoning isconfirmed by measuring levels in
blood, urine or hair samples.,
The most important step in the management of mercury poisoningis
eliminating the source of exposure. The effectiveness ofchelation
therapy in reversing symptoms is not entirely clear.
Our case stresses the potential harm of mercury. It remindsus to
think of a toxic exposure when family members presentwith the same
unusual constellation of symptoms. It also highlightsthe common
misconception that all alternative medicines aresafe and benign.
Michael WeinsteinStacey Bernstein Department of PediatricsHospital for Sick Children Toronto, Ont.
References
Wooltorton E. Facts on mercury and fish consumption. CMAJ
2002;167(8):897.[Free
Full Text]
Exposure to thimersal in vaccines used in Canadian infant
immunization programs, with respect to risk of neurodevelopmental disorders.
Can Commun Dis Rep 2002;28(9):69-80.[Medline]
Dally A. The rise and fall of pink disease. Soc Hist Med
1997;10(2):291-304.[Medline]
Chopra A, Doiphode VV. Ayurvedic medicine: core concept,
therapeutic principles, and current relevance. Med Clin North Am
2002;86(1):75-89.[Medline]
Han RK, Sinclair B, Newman A, Silverman ED, Taylor GW, Walsh P,
et al. Recognition and management of Kawasaki disease. CMAJ 2000; 162
(6): 807-12.[Abstract/Free
Full Text]
Weir E. Methylmercury poisoning [letter]. CMAJ
2001;165(9):1194.[Free
Full Text]
Ruedy J. Methylmercury poisoning [letter]. CMAJ
2001;165(9):1193-4.[Free
Full Text]
Baum C. Treatment of mercury intoxication. Curr Opin Pediatr
1999;11:265-8.[Medline]
American Academy of Pediatrics. Counseling families who choose
complementary and alternative medicine for their child with chronic illness or
disability. Pediatrics 2001;107(3):598-601.[Abstract/Free
Full Text]
ALL INFORMATION, DATA, AND
MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION
PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS
OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR
LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND
COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH
YOUR HEALTH CARE PROVIDER.
"A foolish faith in authority is the worst enemy of truth."
-- Albert Einstein, letter to a friend, 1901
"I know of no safe depository of the ultimate powers of the society but the people themselves, and if we think them not enlightened enough to exercise control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."
-- Thomas Jefferson, letter to William C. Jarvis, September 28, 1820
"What's the point of vaccination if it doesn't protect you from the unvaccinated?"
-- Sandy Gottstein
"Who gets to decide what the greater good is and how many will be sacrificed to it?"