Regarding the clinical features and pathogenesis of herpes simplex virus (HSV) infection of the skin, all of the following statements are correct EXCEPT:

Question

Accepted Answer

C. Tzanck smear from an HSV lesion shows multinucleated giant cells and nuclear molding, which is pathognomonic for HSV and distinguishes it from varicella-zoster virus. ## Analysis of HSV Skin Infection Pathogenesis

### Correct Statements (Options 0, 1, 2)

**Option 0 — Primary vs. Recurrent Infection:**
- Primary HSV is often subclinical or causes mild constitutional symptoms (fever, malaise, lymphadenopathy).
- Recurrent infection is typically preceded by prodromal symptoms (burning, tingling, pain) at the site of reactivation.
- This is a well-established clinical distinction [cite:Park 26e Ch 24].

**Option 1 — Anatomical Latency Sites:**
- HSV-1 latency: trigeminal ganglion (causing recurrent labial herpes).
- HSV-2 latency: sacral dorsal root ganglia (causing recurrent genital herpes).
- This anatomical tropism is fundamental to understanding recurrence patterns [cite:Harrison 21e Ch 187].

**Option 2 — Reactivation from Sensory Ganglia:**
- Latent virus resides in sensory nerve ganglia (not motor nerve endings).
- Upon reactivation, virus travels anterograde along sensory axons to the skin.
- Recurrent lesions appear at the dermatome supplied by the affected sensory ganglion.
- This is the established pathophysiology of recurrent herpes [cite:Robbins 10e Ch 8].

### Incorrect Statement (Option 3) — The Answer

**Key Point:**
**Tzanck smear findings are NOT pathognomonic for HSV.** Multinucleated giant cells and nuclear molding are seen in BOTH HSV and varicella-zoster virus (VZV) infections. Both are herpesviruses and produce identical cytopathic effects on Tzanck smear.

**Clinical Pearl:**
To distinguish HSV from VZV on cytology, additional tests are required:
- Direct fluorescent antibody (DFA) staining with HSV-specific or VZV-specific antibodies.
- PCR (most sensitive and specific).
- Viral culture with HSV/VZV-specific identification.
- Tzanck smear alone cannot differentiate the two viruses.

**High-Yield:**
Tzanck smear is useful for rapid presumptive diagnosis of *any* herpesvirus infection (HSV or VZV), but it is NOT specific for HSV alone. This is a common NEET PG trap.

### Summary Table

| Feature | HSV | VZV | Tzanck Smear |
|---------|-----|-----|---------------|
| Latency site | Sensory ganglia | Sensory ganglia | — |
| Recurrence pattern | Localized, dermatomal | Dermatomal (primary) | — |
| Multinucleated giant cells | Yes | Yes | **Cannot distinguish** |
| Nuclear molding | Yes | Yes | **Cannot distinguish** |
| Specific diagnosis | DFA, PCR, culture | DFA, PCR, culture | Presumptive only |

Answer

A. Primary HSV infection is often asymptomatic or causes mild nonspecific symptoms, whereas recurrent infection typically presents with prodromal symptoms of burning or tingling

Answer

B. Recurrent HSV lesions are preceded by reactivation of virus from latent infection in motor nerve endings within the dermis

Answer

D. HSV-1 preferentially establishes latency in the trigeminal ganglion, while HSV-2 establishes latency primarily in the sacral dorsal root ganglia

Regarding the clinical features and pathogenesis of herpes simplex virus (HSV) infection of the skin, all of the following statements are correct EXCEPT:

Explanation

Practice similar questions