**Question:** Characteristic feature of Herpes Simplex Keratitis is-

A. Inflammation of the cornea
B. Presence of epithelial defects
C. Involvement of the peripheral cornea
D. Symptomatic relief with topical corticosteroids

**Core Concept:**
Herpes Simplex Keratitis (HSK) is an infectious disease of the cornea caused by the herpes simplex virus (HSV), primarily HSV-1. The infection leads to inflammation and ulceration of the cornea, which can result in vision impairment or blindness if left untreated. HSV infections are classified into primary and recurrent infections, with HSK being a common manifestation of recurrent HSV infection.

**Why the Correct Answer is Right:**
The characteristic feature of Herpes Simplex Keratitis is the presence of epithelial defects (Option B). Epithelial defects are a result of the direct cytopathic effects of the virus on the corneal epithelial cells, leading to their destruction and impaired healing. This feature is crucial in distinguishing HSK from other keratitis entities.

**Why Each Wrong Option is Incorrect:**
A. Inflammation of the cornea (Option A) is a feature of HSK, but the correct answer focuses on the specific manifestation of the disease, which is the epithelial defect.

C. Involvement of the peripheral cornea (Option C) is a general description of HSK but does not specifically address the defining feature of the disease.

D. Symptomatic relief with topical corticosteroids (Option D) is a management strategy, not a characteristic feature of HSK.

**Clinical Pearl:**
Herpes Simplex Keratitis is a crucial topic to understand for medical students and practicing physicians due to its potential for vision impairment and blindness. Early diagnosis and appropriate antiviral therapy can significantly improve the prognosis of the disease. Additionally, understanding the difference between primary and recurrent HSK is essential for accurate diagnosis and management.