HHV-6 causes ?
**HHV-6**
### **Core Concept**
HHV-6 (Human Herpesvirus 6) is a member of the herpesvirus family that primarily infects T-lymphocytes. It is known to cause various clinical manifestations, particularly in immunocompromised individuals.
### **Why the Correct Answer is Right**
HHV-6 is responsible for causing roseola infantum (exanthema subitum), a common childhood illness characterized by high fever and a rash that appears after the fever resolves. The virus is transmitted through saliva, respiratory droplets, and possibly through organ transplantation. HHV-6 infects T-lymphocytes, which are a type of white blood cell that plays a crucial role in the immune system.
### **Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because while HHV-6 is a herpesvirus, it is not primarily associated with genital herpes or cold sores, which are more commonly caused by HHV-2 and HHV-1 respectively.
**Option B:** Incorrect because HHV-6 is not directly linked to cancer, although it can cause immunosuppression in transplant patients, making them more susceptible to other infections and malignancies.
**Option C:** Incorrect because while HHV-6 can cause encephalitis, particularly in immunocompromised patients, this is not its most common or well-known manifestation.
### **Clinical Pearl / High-Yield Fact**
Roseola infantum, caused by HHV-6, is characterized by a high fever that resolves before the appearance of a characteristic rash, which typically involves the trunk and extremities.
### **Correct Answer: D. Roseola infantum**