Notes from the Field: Methylmercury Toxicity from a Skin Lightening Cream Obtained from Mexico — California, 2019

Clinical management of chronic mercury intoxication secondary to skin lightening products: A proposed algorithm

“…Measurement of other forms, such as organic mercury levels, is essential in the case of disproportionate clinical manifestation. Most of the studies on chronic symptomatic cases reported the use of skin lightening products with mercury levels exceeding 1000 ppm [3,4,[6][7][8][9][10]12,14,[16][17][18][19]37,38]. However, mercury levels as low as 6.8 ppm have been reported to produce symptoms with longer duration [32].…”

“…Surprisingly, they also detected elevated blood methylmercury levels, an ingredient that is not commonly found in skin whitening products. The poor improvement despite prolonged chelation therapy with DMSA may be due to the presence of a toxic level of methylmercury [6]. Ori et al [14] reported a 17-month girl who was exposed to a www.bjbms.org mercury-containing product with a level of 27,000 ppm for 4-5 months.…”

“…The main symptoms of chronic mercury intoxication are neurological and renal impairment. The neuropsychiatric presentations are usually not specific and may include headache [ 4 , 8 , 9 , 17 , 18 ], dizziness [ 4 , 17 , 18 ], irritability [ 4 , 8 , 13 , 18 ], agitation [ 4 , 19 ], delirium [ 4 , 6 ], seizures [ 9 , 19 ], dementia [ 9 ], fatigue [ 8 , 16 ], pain [ 9 , 13 ], blurry vision [ 6 ], vision changes [ 16 ], speech disturbance [ 6 , 9 ], memory loss [ 8 , 9 , 13 , 16 ], forgetfulness [ 4 , 17 ], disorientation [ 9 ], emotional liability [ 7 ], shyness [ 14 , 19 ], dysthymia [ 19 ], depression [ 4 , 13 , 17 , 18 ], anxiety [ 4 , 13 , 18 ], nervousness [ 8 , 16 ], worriedness [ 18 ], personality changes [ 18 ], decreased concentration [ 18 ], trouble making decision [ 18 ], sleep disturbance [ 4 ], insomnia [ 7 , 8 , 13 ], dreams [ 13 ], tremors [ 7 , 8 , 13 , 19 ], muscle twitching [ …”

“…According to the study conducted in the US, nearly half of the mercury-containing products had a very high mercury level, exceeding 10,000 ppm [2]. Skin-lightening products are manufactured in many countries, such as the UK [3], Mexico [4][5][6][7][8], Lebanon [9], Taiwan [9], Indonesia [10], China [2,11,12], Japan, Thailand, the Philippines, and Jamaica [2]. Both online and physical stores, such as beauty shops, stores [13] and flea markets, as well as relatives and friends [14] contribute to the availability and widespread use of skin lightening products.…”

“…Many case reports showed that patients with chronic mercury intoxication had visited the doctor for the symptoms associated with their current condition but that was not detected. Some of the patients with severe presentation who require hospitalization get proper chelation therapy only after 2–3 weeks from admission due to delayed detection [ 6 , 14 ]. The reasons for the delayed diagnosis and treatment may be 1) non-specific clinical signs and symptoms such as headache and pain, 2) clinical presentation is similar to diseases that may be caused by other etiology such as nephrotic syndrome and systemic lupus erythematous, and 3) lack of knowledge and awareness on chronic mercury intoxication.…”