What is Herpes Zoster?
Herpes Zoster or commonly known as shingles is painful skin rash involving one side of the body following a nerve distribution. It is characterized by blisters or vesicles that eventually break open form open sores. It is caused by the varicella zoster virus which is responsible for causing chickenpox. Once a person has chickenpox, the virus never completely leaves the body but remain dormant inside nerve cells.
Incidence and Risk Factors of Herpes Zoster or Shingles
In healthy people under age 65, the incidence is approximately 1 – 2 cases per 1,000 people per year. In healthy people after age 65, the incidence increases to nearly 10 cases per 1,000 people per year. Patients who are immunosuppressed by drugs or disease have a significant increase in the incidence of herpes zoster.
Pathophysiology of Herpes Zoster or Shingles
The virus normally stays dormant inside the ganglia cells of the nerves of the body. It is not known exactly what triggers the virus to reactivate. A change in the immune status certainly is a major factor. A person who has an active open rash or sores can transmit the virus to someone who never had chickenpox or has not been vaccinated. They would then develop chickenpox not shingles.
Herpes Zoster Ophthalmicus
Herpes Zoster Ophthalmicus or shingles involves the eye and ocular adnexa. The face and ocular area are supplied by the trigeminal nerve. When the virus erupts along the distribution of the nerve, it will follow one of the three branches of the trigeminal. It involves the first division in most cases which supplies sensation to the forehead, front portion of the scalp, upper lid, and in many cases the eye.
Signs and Symptoms of Herpes Zoster
The earlier symptoms may be nonspecific such as not feeling well (malaise), fever, and headaches. Many times people complain of pain in the area of the forehead before any other symptoms occur. Other symptoms that present later are tingling, paresthesia, pins, needles, and stabbing pain. The skin rash appears in a few days. The rash may appear as red bumps or small elevations initially. The rash then becomes the classic blisters or vesicles which break open and eventually crust over. The crusts fall off and the skin gradually heals over weeks of time.
Diagnosis of Herpes Zoster or Shingles
The diagnosis can be difficult in the early stages but once the typical rash appears the diagnosis can be made based on the classic appearance of the rash. Occasionally, Herpes Simplex can have a similar appearance. Laboratory tests and Tzanck smears are available to diagnose Herpes Zoster.
Treatment of Herpes Zoster Ophthalmicus
The aim of treatment is decrease the severity, duration, complications, and long term pain that can occur following an episode of Herpes Zoster.
The routine treatment is Acyclovir 800 mg five times a day for 7 to 10 days.
Famciclovir 500mg three times a day can be used as well.
Valacyclovir 1,000 mg three times a day is another option.
Many doctors still prescribe corticosteroids but there is not convincing evidence that it improves the outcome from Herpes Zoster infection. Some studies have shown that it may decrease the length of healing time and a decrease in pain afterward.
The treatment depends on the ocular involvement. If the cornea and/or the conjunctiva are
Infected it is treated with topical antivirals and antibiotic/steroids medications. A secondary glaucoma can occur which is treated with corticosteroid and glaucoma medications. The uvea, retina, optic nerve, and choroid can become involved and may mean intravenous and intraocular treatment.
Complications of Herpes Zoster
Scarring of the eyelids from zoster can cause lid scarring, ectropion (lid turning out), entropion (lid turning in), ptosis (drooping of the eyelids), and trichiasis (eyelash turning in). Corneal scarring with loss of vision is possible with a keratitis from zoster.
Secondary glaucoma from zoster is known to occur. Damage to the retina, optic nerve, choroid, sclera, and conjunctiva can occur as well. Post neuralgia pain in and around the eye is common and can last for years in some cases.
There is a vaccine for Herpes Zoster called Zostavax. Many doctors recommend it to patients over age 65. It does not guarantee that you will not get an episode of shingles but it greatly decreases the risk.