A 48-Year-Old Man With Tearing and Photophobia

Alissa M. Coyne, OD; Case Series Editor: Jean Marie Pagani, OD


July 25, 2013

Differential Diagnosis

Herpes simplex dendritic keratitis was considered the most likely diagnosis.

Herpes simplex infectious epithelial keratitis may be seen as macropunctate keratitis, a linear branching ulceration with terminal bulbs that have a club-shaped appearance at the end (which is termed a herpetic dendrite) or a geographic ulcer (an amoeba-shaped ulcer with a dendritic edge). The central ulceration in dendritic keratitis and geographic ulcers will stain well with fluorescein dye, and the heaped edges and end bulbs, which contain live virus, will stain with lissamine green or rose bengal.

Infectious epithelial keratitis most often presents with foreign-body sensation, pain, lacrimation, conjunctival hyperemia, and possibly reduced visual acuity. The typical clinical picture shows a dendritic lesion in most cases. Further testing can include corneal sensitivity testing, photodocumentation, and corneal culturing. Diagnosis is often based on the clinical picture, but laboratory studies can confirm suspicious or unusual presentations.

Acanthamoeba keratitis pseudodendrites usually occur in patients with a history of soft contact lens wear. The clinical picture does not match the subjective pain reported by the patient, and the pseudodendrites on the cornea are raised lesions rather than epithelial ulcerations.

Corneal abrasions usually appear as linear lesions, and the patient usually presents with a history of scratching or hitting the eye. Epithelial defects from corneal abrasions stain with fluorescein dye but lack terminal end bulbs.

A resolving recurrent corneal erosion can have a dendritic appearance. Patients with recurrent corneal erosion may have a history of corneal abrasion or dystrophy in the involved eye. Ocular pain, photophobia, and tearing typically occur upon awakening with the removal of epithelial cells, owing to defects in the basement membrane and hemidesmosome formation.

Herpes zoster virus causes painful skin vesicles respecting the midline. Early pseudodendrites can appear the same as herpes simplex keratitis dendrites. However, late pseudodendrites in herpes zoster are mucous plaques and are raised. They also do not have true terminal end bulbs and do not stain well with fluorescein dye. Skin involvement is helpful in differentiating herpes zoster from herpes simplex.


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