Frequent blushing (“erethism”) is associated with : -

Mercury Mechanism of toxicity. Mercury reacts with sulfhydryl (SH) groups, resulting in enzyme inhibition and pathologic alteration of cellular membranes. Clinical presentation. Acute inhalation Severe chemical pneumonitis and noncardiogenic pulmonary edema. Acute gingivostomatitis may also occur. Chronic intoxication Classic triad Neuropsychiatric disturbances Gingivostomatitis. Metallic taste Frequent blushing (“erethism”). Pain in the extremities,often accompanied by pinkish discoloration and desquamation (“pink disease”) Reference – Poisoning & Drug Overdose by Kent R. Olson 3th- 213