Cherry red skin is a late sign of poisoning from which toxin?

• A. Cyanide Poisoning
• B. Methemoglobinemia
• C. Opioid Overdose
• D. Carbon Monoxide Poisoning

Answer: (D)

Cherry-red skin points to carbon monoxide poisoning. Carbon monoxide binds very strongly to hemoglobin, forming carboxyhemoglobin, which gives the blood a bright red color. This makes the skin and mucous membranes appear cherry red in more severe cases. It’s a late sign because it takes time for enough carboxyhemoglobin to accumulate and for tissue hypoxia to become evident. Other toxins don’t produce this characteristic red coloration; for example, methemoglobinemia changes blood color toward chocolate-brown rather than bright red, and opioid overdose presents with respiratory depression and pinpoint pupils rather than a distinctive skin color change.