ACMT Toxicology Visual Pearl: Hypertension and Rash

Answer

3 – Mercury

Background

Mercury poisoning can present as a constellation of symptoms affecting skin, central and peripheral nervous system, cardiovascular, respiratory, musculoskeletal, and genitourinary systems, making diagnosis challenging. Acrodynia, also known as “pink disease”, is a specific syndrome of mercury poisoning causing painful, dusky discoloration of hands and feet which may desquamate. Nonspecific rash resembling viral exanthem is also reported. Mercury inhibits catecholamine-O-methyltransferase (COMT), preventing metabolism of norepinephrine and epinephrine, and causing symptoms similar to pheochromocytoma. Poisoning can also mimic viral illnesses and rheumatologic disorders (1-4). This patient suffered a chronic exposure from an elemental mercury spill on her carpet that had been repeatedly vacuumed.

What are sources of elemental mercury? (1, 5-7)

• Dental amalgams
• Thermometers/manometers
• Fluorescent lights
• Paints
• Complementary medicine
• Industrial exposure such as in electroplating, metal refineries, gold mining, ceramics

What is the clinical presentation of mercury poisoning? (1-7)

• Presentation varies by the type of mercury exposure: elemental, inorganic or organic. Clinical symptomatology is also determined by the route and chronicity of exposure.
• Our patient had elemental mercury exposure which presents as follows:
  • Benign if ingested
  • Becomes vaporized if vacuumed
  • Inhalation of vapor may cause respiratory symptoms within hours, and severe pulmonary toxicity can be progressive and permanent
  • Acute inhalation may also present with rash, weakness, headache, visual disturbances, vomiting, and diarrhea
  • Chronic inhalation exposure may additionally result in tremor, kidney dysfunction, and gingivostomatitis
  • Erethism refers to a syndrome of chronic poisoning resulting in emotional lability, irritability, extreme shyness, delirium, and tremor

How is mercury toxicity treated?

• Remove from exposure and be careful to avoid secondary exposure to providers
• Supportive care
• Decontamination may be indicated depending on the exposure
• Chelation therapy such as with dimercaprol or succimer may be indicated
• Treatment varies by type, route, and chronicity of exposure

Clinical Pearls on Mercury Poisoning

• Never vacuum an elemental mercury spill.
• Poisoning can mimic many other conditions including pheochromocytoma, viral illnesses, or rheumatologic conditions.
• Acrodynia, also known as “pink disease”, is a specific syndrome of mercury poisoning characterized by painful, dusky red rash to hands and feet.
• Erethism refers to neuropsychiatric manifestations of mercury poisoning.
• Chelation therapy may be indicated.

References

1. Sue, YJ. Mercury. In: Nelson LW, Howland MA, Lewin NA, Smith SW, Goldfrank LR, Hoffman RS Eds. Goldfrank’s Toxicologic Emergencies. 11th edition. New York: McGraw-Hill Education, 2019, 1324-1332
2. Yildiz M, Adrovic A, Gurup A, et al. Mercury intoxication resembling pediatric rheumatic diseases: case series and literature review. Rheumatol Int. 2020;40(8):1333-1342. PMID: 32342181
3. Torres AD, Rai AN, Hardiek ML. Mercury intoxication and arterial hypertension: report of two patients and review of the literature. Pediatrics. 2000;105(3):E34. PMID: 10699136
4. Henningsson C, Hoffmann S, McGonigle L, Winter JS. Acute mercury poisoning (acrodynia) mimicking pheochromocytoma in an adolescent. J Pediatr. 1993;122(2):252-253. PMID: 8429442
5. Torres AD, Rai AN, Hardiek ML. Mercury intoxication and arterial hypertension: report of two patients and review of the literature. Pediatrics. 2000;105(3):E34. PMID: 10699136
6. Koirala S, Leinenkugel K. Notes from the Field: Acute Mercury Poisoning After Home Gold and Silver Smelting–Iowa, 2014. MMWR Morb Mortal Wkly Rep. 2015;64(49):1365-1366. Published 2015 Dec 18. PMID: 26678598
7. Kanluen S, Gottlieb CA. A clinical pathologic study of four adult cases of acute mercury inhalation toxicity. Arch Pathol Lab Med. 1991;115(1):56-60. PMID: 1987914