🔑 Key Learning

  • Caused by HSV-1; often affects the cornea causing HSV keratitis
  • Dendritic ulcers are a hallmark finding on fluorescein staining
  • Always refer same day for ophthalmology review
  • Specialist treatment includes antivirals ± topical steroids (under supervision only)

🧬 Pathophysiology

  • HSV-1 causes inflammation in various ocular structures
  • Most commonly affects the corneal epithelium → HSV keratitis
  • Can lead to epithelial ulcers (dendritic) 

👀 Clinical Features

Symptoms

  • Unilateral red eye (in 90% of cases)
  • Non-resolving blepharoconjunctivitis
  • Eye pain, photophobia, watering
  • Blurred vision

Examination Findings

  • Eyelid erythema with vesicles or pustules ± crusting
  • Cloudy or hazy cornea (keratitis)
  • Irregular or fixed pupil if associated uveitis
  • Fluorescein staining: dendritic ulcer with terminal bulbs
Herpes Zoster Ophthalmicus. Herpes_zoster_ophthalmicus.2.jpg: User:Milorad Dimic MDderivative work: DPC, CC BY-SA 3.0 , via Wikimedia Commons

     

🧪 Investigations

  • Fluorescein staining: dendritic branching lesions
  • Slit lamp exam: confirms epithelial or stromal involvement
  • Corneal scrapings or viral PCR swab to detect HSV DNA
Herpes simplex corneal ulcer. Hee K Yang, Young K Han, Won R Wee, Jin H Lee and Ji W Kwon; Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea, CC BY 2.5, via Wikimedia Commons

     

💊 Management

  • Refer urgently for same-day ophthalmology assessment
  • Specialist treatment may include:
    • Topical or oral antivirals (e.g. aciclovir)
    • Topical corticosteroids for stromal disease (only under specialist care)

📝 Exam Clues & Clinchers

  • Dendritic ulcer on fluorescein = HSV keratitis
  • Vesicular lid lesions + red eye = suspect HSV
  • Refer for same day specialist assessment - Topical aciclovir +/- corticosteroids