The keratitis that manifests a branch-shaped figure on the cornea is caused by which pathogen?

• A. Herpes simplex
• B. Fungal keratitis
• C. Bacterial keratitis
• D. Acanthamoeba keratitis

Answer: (A)

Dendritic (branch-like) epithelial ulcers on the cornea are characteristic of herpes simplex keratitis. The herpes simplex virus infects the corneal epithelium and spreads in a branching fashion along epithelial cell borders and corneal nerves, producing a thin, branching ulcer with terminal bulbs. When you use fluorescein staining, these ulcers appear as branching lines with bulbous ends, a pattern that is highly suggestive of HSV keratitis.

This pattern helps distinguish it from other keratitides: acanthamoeba keratitis often causes severe pain with radial keratoneuritis and may develop a ring-shaped infiltrate later; fungal keratitis tends to have feathery-edged ulcers with satellite lesions; bacterial keratitis typically presents with rapid onset of a purulent discharge and a more diffuse stromal/infiltrate appearance.