<prompt> Chocolate cyanosis seen inWilsons diseaseZinc poisoningMethemoglobinemiaMercurialentis  <response>: Methemoglobinemia Signs and symptoms Headache, nausea, vomiting, breathlessness, confusion, coma, convulsion, severe metabolic acidosis. Hemolysis may occur in G6PD deficiency. Blood is chocolate brown in color chocolate cyanosis Ref: FORENSIC MEDICINE AND Toxicology Dr PC IGNATIUS THIRD EDITION PAGE 430 