Other than koplik spots, pathognomonic of measles is:
**Core Concept**
Measles, caused by the measles virus, is a highly contagious respiratory infection characterized by fever, cough, runny nose, and a characteristic rash. The pathophysiology of measles involves the replication of the virus in the respiratory tract, leading to a systemic immune response.
**Why the Correct Answer is Right**
The correct answer is the presence of **coryza**, which is characterized by inflammation of the nasal mucosa and is a hallmark of measles. This occurs due to the replication of the measles virus in the respiratory tract, leading to an influx of neutrophils and monocytes, resulting in nasal discharge and other respiratory symptoms. **Coryza** is a critical clinical feature that helps differentiate measles from other viral infections.
**Why Each Wrong Option is Incorrect**
* **Option A:** While Koplik spots are a pathognomonic sign of measles, they are not the only option listed. The question specifically asks for "other than Koplik spots."
* **Option B:** This option is not directly related to measles and is not a pathognomonic sign of the disease.
* **Option C:** This option is also not directly related to measles and is not a pathognomonic sign of the disease.
**Clinical Pearl / High-Yield Fact**
Coryza is a key feature of measles and can be used to differentiate it from other viral infections. Remember the acronym **CRAM** to aid in remembering the clinical features of measles: **C**oryza, **R**ash, **A**phthous ulcers (Koplik spots), and **M**eningoencephalitis.
**Correct Answer: C. Coryza**