Which of the following is the ‘Least common’ complication of measles?
**Core Concept**
Measles is a highly contagious viral infection caused by the measles virus, leading to complications such as pneumonia, encephalitis, and others. The measles virus affects the respiratory system and immune system, making individuals more susceptible to secondary infections.
**Why the Correct Answer is Right**
Encephalitis, or brain inflammation, is a rare but serious complication of measles. This occurs when the measles virus infects the brain tissue, leading to inflammation and damage to the brain cells. The exact mechanism is not fully understood, but it is believed that the measles virus triggers an immune response that causes damage to the brain tissue. Encephalitis is often associated with high fever, seizures, and altered mental status, and it can have long-term consequences, including cognitive impairment and seizures.
**Why Each Wrong Option is Incorrect**
* **Option A:** Pneumonia is a common complication of measles, especially in young children and individuals with weakened immune systems. It occurs when the measles virus infects the lungs, leading to inflammation and damage to the lung tissue.
* **Option B:** Otitis media, or middle ear infection, is also a common complication of measles, particularly in children. It occurs when the measles virus infects the middle ear, causing inflammation and fluid buildup.
* **Option C:** Conjunctivitis, or pinkeye, is a mild and common complication of measles, occurring when the measles virus infects the conjunctiva, the thin membrane covering the white part of the eye.
**Clinical Pearl / High-Yield Fact**
Measles complications can be prevented by ensuring timely vaccination, especially in high-risk populations such as young children and individuals with weakened immune systems.
**Correct Answer: D. Encephalitis**