Shingles or herpes zoster is a painful and sometimes debilitating viral disease that afflicts close to one million Americans annually. The Herpes Zoster virus can stay in the body for many years, often from the time of a childhood episode of the chickenpox. Patients with herpes zoster are infectious to those who do not have immunity, but less so than patients with varicella. Unlike herpes simplex I, the varicella-zoster virus (VZV) does not for the most part flare up more than once in adults with normally functioning immune systems. As people get older, their immune system naturally weakens to some germs, such as herpes zoster. The virus normally lays dormant in nerve cells, but in certain people the virus reactivates years, or even decades, later and leads to herpes zoster. Anyone who has had the chickenpox infection or vaccine can obtain the herpes zoster virus that causes shingles. Around 20 percent of people who have had chickenpox will develop herpes zoster. Shingles (herpes zoster) most commonly comes about in older adults. The medical term for shingles is acute herpes zoster.
Many herpes zoster patients suffer from chronic pain associated with postherpetic neuralgia. Normally, doctors treat herpes zoster with antiviral medications to lower the incidence and duration of postherpetic neuralgia. Postherpetic neuralgia (PHN) , the pain that sometimes lingers after a bout of shingles (herpes zoster), is the most common and important complication of herpes zoster.
Antibiotic Treatment for Shingles
All patients with acute herpes zoster ophthalmicus ought to receive antiviral therapy with the objective of preventing ocular complications. Descyclovir, famcyclovir, valacyclovir, and pencyclovir are similar to acyclovir and may be used to treat herpes zoster. Tricyclic antidepressants help relieve several of the symptoms, including depression and pain, that affect herpes zoster sufferers with postherpetic neuralgia. Awareness of the complications associated with herpes zoster and recognition of the indications for antiviral treatment are important. Doctors treat herpes zoster with antiviral medications to decrease the incidence and extent of postherpetic neuralgia. Three antiviral drugs are available for the treatment of herpes zoster:
- acyclovir (Zovirax)
- famcyclovir (Famvir)
- valacyclovir (Valtrex)
Famcyclovir or valacyclovir may be used to treat herpes zoster in older children who can swallow pills. Antibiotics prevent infection from other organisms that may get in your eyes while you have herpes zoster. Acyclovir halts progression of herpes zoster in immune compromised patients. Acyclovir is used to treat herpes infections of the skin, lip, and genitals, herpes zoster (shingles), and chickenpox. Valacyclovir and famciclovir are preferred over acyclovir in the treatment of herpes zoster because they have better pharmacokinetic properties and simpler timings for administration. Brivudin, a newer antiviral agent used in treating herpes zoster, is significantly better than standard acyclovir. Brivudin is also as effective as famcyclovir in alleviating acute signs and symptoms of herpes zoster. Acute pain responds to prompt treatment of herpes zoster, and immediate therapy lessens the duration of pain in PHN patients. Patients should be advised to initiate treatment as soon as possible after a diagnosis of herpes zoster.
The pain and discomfort of the active herpes zoster infection is the primary symptom and complication of herpes zoster. Further potentially serious complications can result from herpes zoster. Encephalitis and pneumonia are rare complications of herpes zoster. Disseminated zoster is much more likely to occur in immune compromised individuals. As with disseminated chickenpox, disseminated herpes zoster, which spreads to other organs, can be serious to life-threatening, especially if it affects the lungs. These patients can develop chronic herpes zoster, with formation of new lesions without the healing of the already existing ones. Inflammation of the membrane around the brain (meningitis) or in the brain itself (encephalitis) is a rare complication in people with herpes zoster. If it occurs as a consequence of herpes zoster, brain inflammation tends to be mild except in immune compromised patients. Herpes zoster could recur, because the virus can stay in the nerve cells at the base of the spine for decades. Rarely, however, the pain of herpes zoster impacts sleep, mood, work, and overall quality of life. Studies are being undertaken to see if varicella vaccine can boost cellular immunity of older individuals so that herpes zoster can be prevented.
The pain associated with herpes zoster is believed to be due to irritation of the sensory nerve fibers in which the virus reproduces. Shingles lesions are normal at the onset but may turn into ulcers that do not heal. After a chickenpox infection, the virus stays dormant in sensory nerve cell bodies.
Shingles-Induced Eye and Ear Disease
A patient with herpes zoster on the face should see a physician immediately, because infection of the eye might lead to blindness. Without antivirals, 50%-70% of herpes zoster ophthalmicus cases develop ocular complications. Antiviral therapy is mandatory for patients with herpes zoster ophthalmicus, mainly to prevent potentially sight-threatening ocular complications. Early diagnosis and care can assist greatly in diminishing serious complications from herpes zoster eye infections. Fortunately, blindness following herpes zoster is rare. If the eyes become involved (herpes zoster ophthalmicus), a significant infection can occur that is difficult to treat and can threaten vision. Ramsay Hunt syndrome (also called herpes zoster oticus) occurs when herpes zoster involves the nerves in the face and ears. Ramsay Hunt syndrome type I, also known as herpes zoster oticus, is a typical complication of shingles. Ramsay Hunt syndrome occurs when herpes zoster causes facial paralysis and rash on the ear (herpes zoster oticus) or mouth. Because herpes zoster oticus is a rare disease with good prognosis for survival, there is little neuropathologic material available. Ten percent to 15% of cases of herpes zoster involve the ophthalmic branch of the trigeminal nerve.
Shingles is caused by a particular type of herpes virus, varicella zoster. Varicella zoster virus is a member of the herpesvirus family. VZV is an alphaherpesvirus that causes two diseases, chickenpox and zoster (the reactivation of the virus that causes shingles). Like other herpes viruses, the varicella-zoster virus has an initial infectious stage (chickenpox) followed by an inactive stage. Like its close relative, HHV1, herpes zoster likes to infect skin cells and nerve cells. Reactivation of the latent virus in neurosensory ganglia produces the characteristic manifestations of herpes zoster, commonly known as shingles. In 1888, it was indicated by von Bokay that chickenpox and herpes zoster were due to the same causal agent, now known to be the VZV virus. Shingles (herpes zoster) is a viral infection of the nerve roots.
A varicella-zoster virus vaccine reduced the burden of illness of herpes zoster in older adults. Zostavax is a vaccine intended for the prevention of herpes zoster (shingles) and herpes zoster related postherpetic neuralgia (PHN). The vaccine challenge reactivates cellular immunity to VZV, preventing or weakening occurrence of herpes zoster. The zoster vaccine markedly reduced mortality from herpes zoster and postherpetic neuralgia among older adults. In some cases a mild narcotic is needed to control the burning pain associated with herpes zoster. Aluminum acetate or soaks with burrow solution can be both soothing and cleansing in patients with herpes zoster. In contrast to their effect on herpes simplex infections, topical steroids do not exacerbate herpes zoster infections.
MRI findings in cases of herpes zoster myelitis are typically abnormal, but non-specific. The pain of Herpes Zoster can be quite intense as the nerve endings are affected. In contrast with the pain of trigeminal neuralgia, the pain of herpes zoster is steady and sustained.
Herpes Zoster Risk Factors
Immune compromised persons, particularly those with human immunodeficiency virus (HIV) infection, have a significantly higher risk of developing herpes zoster ophthalmicus than the normal population. With more advanced immunodeficiency, herpes zoster tends to become generalized. The occurrence of herpes zoster goes up with age, and is associated with age-related typical waning in cell-mediated immunity. The incidence of herpes zoster in HIV-infected individuals is the same as age-matched HIV-negative persons. Up to 15 % of those who have had varicella disease will have herpes zoster at some point in their lives. If the person's immunity is intact, herpes zoster is mainly self-limited. Researchers noted a high incidence of herpes zoster after psychic trauma. Cancer places people at risk for herpes zoster. Chemotherapy boosts the risk for herpes zoster. Approximately 10 percent to 15 percent of all patients with herpes zoster develop PHN, which, once established, can persist for many years.
Shingles and chickenpox are caused by herpes zoster. The same virus that causes chickenpox causes shingles (herpes zoster). Chicken pox is caused by the varicella zoster virus.
There is no agreement on how acute herpes zoster (shingles) should be managed in general practice. Localized herpes zoster requires secretion precautions to guard against spreading of infection by direct contact with secretions from vesicles and from secretion-contaminated articles. In individuals with damaged immune systems, herpes zoster could be widespread (disseminated), causing serious illness. Although anyone who has had chickenpox can subsequently have herpes zoster (shingles), it is much more common in individuals older than 50 years. The virus causing herpes zoster (shingles) is already present from an earlier infection with chickenpox.
The incidence and severity of herpes zoster and PHN increase with advanced age. The virus that causes shingles (herpes zoster) can be passed on to others, but they will develop chickenpox, not shingles. Unlike herpes simplex I, the varicella-zoster virus does not typically flare up more than once in adults with normally functioning immune systems. People with herpes zoster are thought to be contagious to persons who have never had chickenpox. You experience herpes zoster or shingles from your own chickenpox virus, not from someone else. Once approved, vaccination will become the main strategy to prevent herpes zoster and postherpetic neuralgia. People who have never had chickenpox can catch chickenpox if they have close contact with a person who has herpes zoster or shingles. By its very nature, herpes zoster infections are prone to return from time to time, especially when the immune system is weakened.