Cause of Herpes Zoster ?
**Core Concept**
Herpes zoster, also known as shingles, is a viral infection caused by the reactivation of the varicella-zoster virus (VZV) in individuals who have previously had chickenpox. The virus remains latent in the dorsal root ganglia of spinal nerves and can reactivate due to various factors.
**Why the Correct Answer is Right**
The correct answer is due to the reactivation of the latent varicella-zoster virus (VZV) in the dorsal root ganglia of spinal nerves. This reactivation leads to the production of new viral particles, which then travel down the nerve fibers and cause the characteristic skin lesions of herpes zoster. The virus also causes inflammation of the affected nerve and surrounding skin, resulting in pain, itching, and blistering.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the cause of herpes zoster is the reactivation of the latent varicella-zoster virus, not a bacterial infection.
**Option B:** This option is incorrect because herpes zoster is not caused by a fungal infection, but rather by the reactivation of a viral infection.
**Option C:** This option is incorrect because while stress can trigger the reactivation of the latent varicella-zoster virus, it is not the primary cause of herpes zoster.
**Clinical Pearl / High-Yield Fact**
The varicella-zoster virus can reactivate in individuals with weakened immune systems, such as those with HIV/AIDS, cancer, or taking immunosuppressive medications. This highlights the importance of maintaining a healthy immune system to prevent reactivation of latent viruses.
**Correct Answer: D. Reactivation of latent varicella-zoster virus.**