Fever blisters can occur due to:
**Core Concept**
Fever blisters, also known as cold sores, are a type of recurrent herpes simplex virus (HSV) infection that affects the skin. They are caused by the reactivation of latent HSV-1 virus in the nervous system.
**Why the Correct Answer is Right**
HSV-1 infects the nerve cells in the skin, specifically the trigeminal nerve ganglion, and remains latent until reactivation occurs, often triggered by stress, sunlight, or fever. During reactivation, the virus travels down the nerve fibers to the skin, causing inflammation and the characteristic blister-like lesions. The correct answer is related to the pathogenesis of HSV-1 infection.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because HSV-1 is not primarily associated with genital herpes, which is caused by HSV-2.
**Option B:** This option is incorrect because HSV-2 is not the primary cause of fever blisters (cold sores).
**Option C:** This option is incorrect because varicella-zoster virus (VZV) causes chickenpox and shingles, not fever blisters.
**Clinical Pearl / High-Yield Fact**
HSV-1 can be transmitted through skin-to-skin contact, even when the lesions are not visible, and can also be spread through saliva, making it essential to practice good hygiene, especially during outbreaks.
**Correct Answer: D. HSV-1**