Review Question - QID 105380

Herpes simplex virus keratitis presents as an infection of the superficial cornea with diffuse dendritic lesions on the corneal epithelium. The treatment is with oral acyclovir.

In herpes simplex virus keratitis, patients may present with pain, blurry vision, and watery discharge. Ocular manifestations of HSV-1 are not limited to keratitis but may also be conjunctivitis, blepharitis, retinitis, and scleritis so the remainder of the eye should be examined. Corneal pathology, however, is the most often. The treatment of HSV keratitis is dependent upon whether the episode of disease is caused by active viral replication or immune response to past infection. Oral and topical antivirals are equally effective, but oral agents are more convenient to use.

Usatine and Tinitgan discuss nongenital herpes simplex virus. HSV-1 is usually transmitted during childhood during nonsexual contact. Most of these infections involve the oral mucosa or lips (herpes labialis). Other nonoral herpes simplex virus type 1 infections include herpetic keratitis, herpetic whitlow, herpes gladiatorum, and herpetic sycosis of the beard area. In cases of herpatic keratitis where treatment is delayed, scarring of the cornea may occur.

Rowe et al. discuss HSV-1 ocular infection. More often HSV-1 ocular infections result from reactivation of virus that originally established a latent infection in the TG following a non-ocular route of infection. Reactivation of latent virus in the ophthalmic branch of the TG can result in shedding at the corneal surface. HSV-1 corneal lesions can either be restricted to the corneal epithelium, or have stromal involvement with or without damage to the overlying epithelium.

Figure A depicts the dendritic pattern in HSV keratitis on exam. Illustration A shows the classic appearance of Map-Dot-Fingerprint dystrophy. Illustration B shows orbital cellulitis. Illustration C shows a keratinized and vascularized cornea as a result of Stevens-Johnson Syndrome.

Incorrect Answers:
Answer 1: Applying topical glucocorticoid drops without the use of antiviral medication could worsen the infection and threaten vision.
Map-dot-fingerprint dystrophy occurs when the epithelium’s basement membrane develops abnormally causing the epithelial corneal cells to not properly adhere to it. This results in recurrent epithelial erosions. Sometimes on exam, the irregular basement membrane will form concentric lines in the central cornea that resemble small fingerprints.
Answer 2: Laboratory testing is not needed to confirm the diagnosis. The diagnosis is most often made clinically and in this case there is ample clinical evidence to suggest a dose of HSV keratitis. Further serologic testing is often not helpful because of the high prevalence of exposure in the population.
Answer 3: Intravenous antibiotics would be indicated in orbital cellulitis.
Answer 4: Stevens-Johnson syndrome is marked by a drug reaction where the cornea may become keratinized and vascularized leading to blindness. It is not characterized by a dendritic pattern on corneal examination.