Cornea
Herpes Simplex Keratitis
Also known as: HSK, herpes simplex keratitis, HSVK, dendritic ulcer, herpetic keratitis, herpetic epithelial keratitis, HSV keratitis, geographic ulcer
Filed as: Urgent
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
Corneal infection caused by herpes simplex virus type 1 (HSV-1). The most common cause of infectious corneal blindness in developed countries. Presents as a spectrum from dendritic epithelial ulcer (classic) to disciform stromal keratitis to endotheliitis. Recurrent disease causes progressive corneal scarring. Avoid topical steroids in epithelial HSV unless ophthalmology directs their use.
Recognition
Symptoms: what patients report
- Unilateral eye pain or irritation — can be mild to moderate in epithelial disease.
- Photophobia.
- Tearing and watering.
- Redness.
- Blurred vision — especially in stromal disease.
- Reduced corneal sensation (anaesthesia or hypoaesthesia) — a key finding in HSV keratitis.
- History of previous episodes, cold sores, or perioral herpes simplex.
- Recurrences may be triggered by UV exposure, fever, stress, or immunosuppression.
Signs: what the examination shows
- Dendritic ulcer: a branching, linear epithelial defect with terminal bulbs — classic for HSV epithelial keratitis. Stains with fluorescein.
- Geographic ulcer: large irregular amoeboid epithelial defect — advanced epithelial disease or metaherpetic/indolent ulcer.
- Stromal keratitis (immune stromal): corneal oedema, Descemet's folds, stromal haze — no epithelial defect. Disciform pattern common.
- Disciform keratitis: disc-shaped central corneal oedema with a clear epithelium — HSV endotheliitis variant.
- Reduced corneal sensation — compare with the fellow eye where feasible; reduced sensation strongly supports HSV and neurotrophic risk.
- Periorbital vesicles or skin lesions may be present in primary HSV.
What OptoGuide™ covers for herpes simplex keratitis
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked Australian therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Herpes simplex keratitis (HSK) — College of Optometrists CMG
- Anterior Eye Disease and Therapeutics A-Z (Bruce & Loughnan) — standard reference text
- Antiviral Treatment and Other Therapeutic Interventions for Herpes Simplex Virus Epithelial Keratitis. Wilhelmus KR. The Cochrane Database of Systematic Reviews. 2015;1:CD002898.
- Infectious Keratitis in 2021. Durand ML, Barshak MB, Chodosh J. JAMA. 2021;326(13):1319-1320.
- Differentiation of acanthamoeba keratitis from other non-acanthamoeba keratitis: Risk factors and clinical features. Alreshidi SO, Vargas JM, Ahmad K, et al. PloS One. 2024;19(3):e0299492.
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, The Wills Eye Manual, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.