Cherry Red Skin is a late sign of CO poisoning.

• A. Late sign of CO poisoning
• B. Blue tinted skin
• C. Early sign of inhalation injury
• D. No skin changes

Answer: (A)

In carbon monoxide poisoning, the primary issue is that CO binds tightly to hemoglobin, forming carboxyhemoglobin and preventing oxygen from being carried to tissues. Early signs are nonspecific—headache, dizziness, confusion, nausea—so clinicians don’t rely on skin color to spot the problem. The red or cherry-colored skin sometimes described in CO poisoning is not common and, when it appears, it tends to show up late in the course, reflecting severe carboxyhemoglobinemia. Because it’s neither reliable nor early, labeling cherry-red skin as a late sign best fits the statement. Other choices don’t align with the typical progression: blue-tinted skin would suggest cyanosis from severe hypoxemia but isn’t a classic CO finding, early skin changes aren’t characteristic, and saying there are no skin changes ignores the rare late presentation. In practice, treat presumptively with high-flow oxygen and confirm with carboxyhemoglobin measurement rather than waiting for a skin color change.