A 32-year-old woman presents with a 5-day history of unilateral eye pain, photophobia, and blurred vision. On examination, the cornea shows a dendritic ulcer with terminal bulbs staining with fluorescein. Conjunctival injection and preauricular lymphadenopathy are noted. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis The dendritic ulcer with terminal bulbs and fluorescein staining is pathognomonic for **herpes simplex virus (HSV) keratitis**. The constellation of unilateral pain, photophobia, and preauricular lymphadenopathy confirms the diagnosis. **Key Point:** Dendritic ulcer = HSV keratitis until proven otherwise. Do not delay treatment while awaiting culture results. ## Management Algorithm ```mermaid flowchart TD A[Dendritic ulcer on exam]:::outcome --> B{Confirmed HSV keratitis?}:::decision B -->|Yes - Epithelial disease| C[Topical acyclovir 5% ointment<br/>5 times daily]:::action C --> D[Add oral acyclovir<br/>400 mg 5 times daily × 10 days]:::action D --> E[Avoid topical steroids<br/>in epithelial disease]:::urgent B -->|Stromal/endothelial involvement| F[Consider topical steroid<br/>+ acyclovir after epithelial healing]:::action A --> G[Preauricular lymphadenopathy<br/>is expected finding]:::outcome ``` ## Treatment Rationale **High-Yield:** HSV epithelial keratitis responds rapidly to topical acyclovir ointment. Oral acyclovir reduces recurrence risk and systemic viral load. | Drug | Indication | Dosing | Duration | |------|-----------|--------|----------| | Topical acyclovir 5% ointment | Epithelial HSV keratitis | 5 times daily | Until re-epithelialization (7–10 days) | | Oral acyclovir | Systemic suppression + epithelial disease | 400 mg 5× daily | 10 days | | Topical steroids | Stromal/endothelial disease ONLY | After epithelial healing | Avoid in epithelial phase | **Clinical Pearl:** Preauricular lymphadenopathy is a normal host response to HSV and does not indicate CNS involvement. It resolves with systemic antiviral therapy. **Warning:** Do NOT use topical steroids in epithelial HSV keratitis — they promote viral replication and cause geographic/amoeboid ulceration (herpes simplex keratouveitis). ## Why Immediate Treatment? 1. Epithelial HSV keratitis is self-limited but acyclovir accelerates healing (7–10 days vs. 2–3 weeks). 2. Early treatment reduces risk of stromal involvement and scarring. 3. Viral culture takes 5–7 days; clinical diagnosis is sufficient to initiate therapy. [cite:Khurana Comprehensive Ophthalmology Ch 3]