The special challenges of herpes zoster ophthalmicus include the risks of glaucoma and corneal scarring.
Varicella zoster is an opportunistic adversary. The virus initially causes chickenpox and then burrows into the central nervous system for a period of inactivity. Decades later it can reactivate when the person’s immune system is compromised, spreading through peripheral nerves to cause shingles (herpes zoster). If the virus has been laying dormant within the ophthalmic nerve, it re-emerges as herpes zoster ophthalmicus (HZO), a subtype of shingles that accounts for up to 20% of all cases.
The American Academy of Ophthalmology (AAO) considers HZO, also called ocular shingles, to be a growing risk. It notes that the incidence rate of both shingles and HZO worldwide rose 39% between 1992 and 2010. The age of onset also appears to be dropping, increasing the number of potential patients.
Early symptoms of HZO include fever and headache followed by a tingling of the scalp and forehead. Within days a unilateral vesicular rash develops within the dermatome, including the upper eyelid and nose. One clinical sign of HZO is a vesicle on the tip of the nose that’s known as Hutchinson’s sign.
Rebecca J. Taylor, MD, an ophthalmologist in private practice in Nashville, says that pharmacists can play an important role in identifying HZO in its earliest stages. “If a person comes in and says, ‘I’m having burning and tingling in my scalp, and I’ve felt sick for the last couple of days’, that’s pretty classic for HZO,” she explains. “The next question would be, ‘Have you noticed any bumps on your forehead or scalp?’” Patients should be referred to a physician, she says. Taylor is a clinical spokesperson for the AAO.
Taylor also recommends that patients see their ophthalmologist when HZO is suspected. If left untreated, 50% to 70% of HZO patients develop acute ocular complications. In addition to pain and redness, complications include swelling of the eyelid, sensitivity to light, keratitis, pseudodendrites, uveitis, glaucoma, and neurotrophic disease. Corneal inflammation and scarring, blindness, and visual impairment can also occur, sometimes months or years later.
The AAO recommends systemic antiviral therapy within three days of the initial symptoms or rash to help reduce the incidence or severity of serious sequelae. The odds of developing postherpetic neuralgia are greater in patients with HZO, as are stroke, temporal arteritis, heart attack, and depression, the organization notes.
“Patients with HZO not only are treated with oral acyclovir or famciclovir, but also with topical steroids,” explains Taylor. “It’s very helpful for the corneal disease, for calming down the inflammation on the inside of the eye which leads to glaucoma, and for treating the deeper layers of the eye. IV administration can even be considered.”
Daily washing and dressing of the affected areas with clean, fresh bandages is recommended. Patients should be told to avoid touching the rash and keep it covered to reduce the risk of transmitting the virus. Scrupulous handwashing following contact with the blisters or bandages is also critical to avoid cross infection.
The first line of defense against shingles and HZO is vaccination. The AAO advises that ophthalmologists recommend it to their eligible patients age 50 years and older.