Which toxic exposure can present with the pictured rash along with hypertension and tachycardia mimicking pheochromocytoma?
- Arsenic
- Lead
- Mercury
- Silver
- Thallium
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
- 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
- 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
- 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
- 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
- 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
- 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
- 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