A worker is employed in a factory where he is exposed to organic mercury compounds. Which of the following target organ manifestations is MOST specific to organic mercury toxicity compared with inorganic mercury?

• A Renal tubular necrosis
• B Stomatitis and salivation (mercurialism)
• C Cerebellar ataxia, constriction of visual fields, and sensorineural deafness ✓
• D Blue-black line on gingival margin (Burton's line)

Explanation

Organic mercury (methylmercury, as in Minamata disease) is highly lipophilic and preferentially affects the CNS — specifically causing cerebellar ataxia, constriction of visual fields (tunnel vision), dysarthria, and sensorineural deafness (Hunter-Russell syndrome). Inorganic mercury primarily causes renal tubular damage, stomatitis, excessive salivation, and tremor. Burton's line (blue-black gingival line) is characteristic of chronic LEAD poisoning, not mercury. Mercurialism with salivation and gingivitis is inorganic mercury toxicity.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.