Updated: Jun 1, 2009
Varicella-zoster virus (VZV) is the agent causing chickenpox, the common childhood infection. Following resolution of chickenpox, VZV lies dormant in the spinal dorsal root ganglia until reactivation results in herpes zoster (shingles). "Shingles" is a syndrome characterized by a painful, unilateral vesicular rash, usually restricted to a dermatomal distribution. At times, especially in the immunosuppressed patient, the infection may spread and produce severe systemic illness with involvement of multiple visceral organs and multiple dermatomes (disseminated zoster).
Shingles usually has a benign course, but complications may occur, ranging from mild to life-threatening. Complicated herpes zoster refers to infections occurring in immunosuppressed patients or manifested by ocular involvement. In properly selected patients, early treatment with antivirals and possibly corticosteroids has been shown to decrease the duration of illness and to prevent or ameliorate some complications.
Exactly why VZV reactives from latency is not fully understood. However, VZV-specific cell-mediated immunity has been shown to be a major factor in determining reactivation of VZV. Cell-mediated VZV-specific immunity decreases with age and in patients with certain malignancies. These groups have much higher rates of herpes zoster. Patients with hypogammaglobulinemia (a defect of humoral but not cellular immunity) do not have a higher rate of zoster. This supports the concept of an important role for cell-mediated immunity in the pathogenesis of VZV infection.
VZV reactivation causes inflammation in the dorsal root ganglion accompanied by hemorrhagic necrosis of nerve cells. The result is neuronal loss and fibrosis. The distribution of the rash corresponds to the sensory fields of the infected neurons within a specific ganglion. The anatomic location of the involved dermatome often determines the specific manifestations (eg, herpes zoster ophthalmicus causing ocular complications when the trigeminal ganglion is involved).
Approximately 95% of adults in the United States have antibodies to the varicella-zoster virus and are vulnerable to reactivation infection. A person of any age with a prior varicella infection may develop zoster, but incidence increases with advancing age due to declining immunity. Approximately 4% of patients with zoster will develop a recurrent episode later in life.
A study of patients in a large health maintenance organization (HMO) in the United States revealed 1075 cases from 1990-1992.1 The following characteristics were noted:
Blacks are one-fourth as likely as whites to develop herpes zoster.
Incidence is equal in males and females.
Incidence of herpes zoster increases with age. Approximately 80% of cases occur in persons older than 20 years. Fewer than 5% of cases are in those younger than 14 years.
Prodromal pain precedes the rash in approximately 75% of patients, typically confined to the same dermatomal distribution. Initially vesicular, the rash gradually becomes pustular and then crusts over a period of 7-10 days. As with chickenpox, once crusting occurs, the lesion is no longer infectious. Scarring and hypopigmentation or hyperpigmentation may persist for a long period.
Herpes zoster is caused by reactivation of VZV as described in Pathophysiology.
| Appendicitis, Acute | Herpes Simplex |
| Bell Palsy | Herpes Zoster |
| Cholecystitis and Biliary Colic | Herpes Zoster Ophthalmicus |
| Conjunctivitis | Herpes Zoster Oticus |
| Corneal Ulceration and Ulcerative
Keratitis | Renal Calculi |
| Glaucoma, Acute Angle-Closure | Trigeminal Neuralgia |
Coxsackievirus
Superficial pyoderma
No imaging tests are indicated in typical cases of cutaneous VZ infection.
Symptomatic treatment
Antiviral therapy for uncomplicated herpes zoster
The goals of antiviral therapy are to decrease pain, to promote healing of skin lesions, and to prevent or reduce the severity of postherpetic neuralgia. Acyclovir and the newer antivirals valacyclovir and famciclovir have been shown to be effective if given within 48-72 hours of the appearance of the rash. The newer agents have better bioavailability and do not need to be given as frequently. Outcomes studied have included time to crusting of skin lesions, duration and severity of acute pain, and duration and incidence of postherpetic neuralgia.4
Acyclovir has been the most studied and widely recommended, but in a blinded, randomized comparison trial, valacyclovir was shown to be superior to acyclovir.5,6 The trial included more than 1100 patients with uncomplicated zoster who were 50 years or older. Adverse effects were similar in both groups. Outcomes evaluated included resolution of acute pain and the duration of postherpetic neuralgia.
The duration of antiviral treatment in studies has varied from 7-21 days. Based on current literature, for immunocompetent patients, acyclovir for 7-10 days or a 7-day course of the newer agents is appropriate. Longer courses may be needed in immunocompromised patients.
Combined antiviral and corticosteroid therapy for uncomplicated herpes zoster
The addition of corticosteroids has been evaluated in patients treated with acyclovir. The benefit of steroids included accelerated healing of lesions and more rapid resolution of acute pain.7 Though statistically significant, the benefits were small. There was no effect on the development or duration of postherpetic neuralgia.
Steroids have not been studied with valacyclovir of famciclovir, so the benefit is unknown. The addition of steroids should be considered only in patients with severe symptoms. Steroids should not be given alone (without antiviral therapy) due to concern about promotion of viral replication. The effect of steroids on the incidence of secondary skin infection is unknown. Some authors have suggested that they may increase the risk. Prednisone, 40-60 mg/day, is a reasonable choice if steroids are used. The optimal duration of steroid therapy is not known. If prescribed, it seems reasonable for steroids to be used concurrently with antiviral therapy. The duration of steroid use should not extend beyond the period of antiviral therapy.
Treatment of complicated herpes zoster
Patients who are immunosuppressed are at risk for extensive skin involvement or disseminated disease. Although strong evidence is lacking, the following are highlights of some of the current recommendations for treating zoster in these patients.
Treatment of herpes zoster ophthalmicus
Two trials comparing oral acyclovir to famciclovir or valacyclovir in patients with ophthalmic zoster showed comparable outcomes with any of the regimens.8 Patients with diagnosed or suspected ophthalmic zoster should receive antivirals and be referred to an ophthalmologist.
Post exposure prophylaxis
Varicella-zoster immune globulin (VZIG) prevents or modifies clinical illness in susceptible, persons who are exposed to varicella or zoster. It should be reserved for patients at risk for complications such as those who are immunocompromised, pregnant, and for neonates.9
Goals of therapy in herpes zoster infection are to (1) shorten the clinical course, (2) provide analgesia, (3) prevent complications, and (4) decrease incidence of postherpetic neuralgia. Meta-analyses and randomized controlled trials suggest that the oral antiviral agents acyclovir, famciclovir, and valacyclovir started within 72 hours of the onset of rash reduce both the severity and the duration of acute pain, as well as the incidence of postherpetic neuralgia.
Acyclovir antivirals may decrease incidence of postherpetic neuralgia. Famciclovir and valacyclovir (2 antiviral agents with properties similar to those of acyclovir) offer better dosing regimens than acyclovir and yet are less studied.
Reduces duration of symptomatic lesions. Indicated for patients who present within 48 h of onset of rash. Treated patients experience less pain and faster resolution of cutaneous lesions.
800 mg PO q4h (5 times/d) for 7-10 d; alternatively, 10 mg/kg/dose or 500 mg/m2/dose IV q8h
250-600 mg/m2/dose PO 4-5 times/d for 7-10 d; alternatively, 10 mg/kg/dose or 500 mg/m2/dose IV q8h
Probenecid or zidovudine prolongs half-life and increases CNS toxicity
Documented hypersensitivity
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Caution with renal failure or coadministration of other nephrotoxic drugs
Prodrug that, when biotransformed into active metabolite penciclovir, may inhibit viral DNA synthesis/replication.
500 mg PO q8h for 7 d
Not established
Probenecid or cimetidine may increase toxicity; increases bioavailability of digoxin
Documented hypersensitivity
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Caution in renal failure or coadministration of nephrotoxic drugs
Prodrug rapidly converted to acyclovir before exerting its antiviral activity. More expensive but more convenient dosing regimen than acyclovir.
1000 mg PO q8h for 7 d
Not established
Probenecid, zidovudine, or cimetidine prolongs half-life and increases CNS toxicity
Documented hypersensitivity
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Caution in renal failure and coadministration of nephrotoxic drugs; associated with onset of hemolytic uremic syndrome
These agents have anti-inflammatory properties and cause profound and varied metabolic effects. Corticosteroids modify the body's immune response to diverse stimuli. The addition of oral prednisolone to acyclovir treatment has been shown to reduce pain, to speed healing of lesions, and to enable a more rapid return to daily activities.
The addition of a corticosteroid to acyclovir resulted in decreased acute pain but no decrease in long-term pain. One study also demonstrated more rapid initial healing of rash, although time to complete rash resolution was unchanged.
60 mg/d PO tapered over 3 wk
0.05-2 mg/kg PO divided bid/qid; taper over 2 wk
Coadministration with estrogens may decrease clearance; concurrent use with digoxin may cause digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism of glucocorticoids (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics
Documented hypersensitivity; viral, fungal, tubercular skin, and connective tissue infections; peptic ulcer disease; hepatic dysfunction; GI bleeding or ulceration
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Abrupt discontinuation of glucocorticoids may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections may occur with glucocorticoid use
Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and enable physical therapy regimens. Most analgesics have sedating properties that are beneficial for patients who have skin lesions.
DOC for treatment of pain in patients who (1) have documented hypersensitivity to aspirin or NSAIDs, (2) have upper GI disease, or (3) are taking oral anticoagulants. Reduces fever by direct action on hypothalamic heat-regulating centers, which increases dissipation of body heat via vasodilation and sweating.
325-650 mg PO q6h, or 1000 mg tid/qid; not to exceed 4 g/d
<12 years: 10-15 mg/kg/dose PO q4-6h prn; not to exceed 2.6 g/d
>12 years: 650 mg q4h; not to exceed 5 doses in 24 h
Rifampin can reduce analgesic effects; barbiturates, carbamazepine, hydantoins, and isoniazid may increase hepatotoxicity
Documented hypersensitivity; known G-6-P deficiency
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Hepatotoxicity possible in chronic alcoholics following various dose levels; severe or recurrent pain or high or continued fever may indicate serious illness; acetaminophen is contained in many OTC products, and combined use with these products may result in cumulative acetaminophen doses exceeding recommended maximum dose
DOC for treatment of mild to moderately severe pain, if no contraindications. Inhibits inflammatory reactions and pain, probably by decreasing activity of enzyme cyclooxygenase, in turn, inhibiting prostaglandin synthesis. One of few NSAIDs indicated for reduction of fever.
200-400 mg PO q4-6h while symptoms persist; not to exceed 3.2 g/d
<16 years: Not recommended because of association with Reye syndrome
>16 years: Administer as in adults
Aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity; may decrease effects of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; may increase PT in patients taking anticoagulants (monitor PT closely and instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; may increase phenytoin levels
Documented hypersensitivity; peptic ulcer disease; recent GI bleeding or perforation; renal insufficiency; high risk of bleeding
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Caution in congestive heart failure, hypertension, and decreased renal and hepatic function; caution in coagulation abnormalities or during anticoagulant therapy
These agents elicit active immunization to increase resistance to infection. Vaccines consist of attenuated microorganisms or cellular components, which act as antigens. Administration stimulates antibody production with specific protective properties.
Lyophilized preparation of Oka/Merck strain of live, attenuated varicella-zoster virus (VZV). Shown to boost immunity against herpes zoster virus (shingles) in older patients. Reduces occurrence of shingles in individuals >60 y by about 50%. For individuals aged 60-69 y, it reduces occurrence by 64%. Also slightly reduces pain compared with no vaccination in those who develop shingles. Indicated for prevention of herpes zoster in patients >60y who have no contraindications.
<60 years: Not established
>60 years: Following reconstitution with entire vial of diluent supplied, use separate sterile needle and syringe to withdraw entire contents of reconstituted vial and administer SC; administer in upper arm
Not indicated
None reported
Documented hypersensitivity to vaccine or components (eg, gelatin, neomycin); history of primary or acquired immunodeficiency states (eg, leukemia, lymphomas, malignant neoplasms affecting bone marrow or lymphatic system, AIDS); immunosuppressive therapy including high-dose corticosteroids; active, untreated tuberculosis
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Common adverse effects include erythema, pain, tenderness, itching, and inflammation at injection site; may also cause headache; may cause extensive vaccine-associated rash or disseminated disease in individuals on immunosuppressive therapy (see Contraindications); defer vaccination if fever or acute illness present; do not inject intravascularly; administer within 30 min of reconstitution; not a substitute for varicella virus vaccine (Varivax) for children
Complications of herpes zoster may include the following:
Donahue JG, Choo PW, Manson JE, Platt R. The incidence of herpes zoster. Arch Intern Med. Aug 1995;155(15):1605-9. [Medline].
[Best Evidence] Dworkin RH, Barbano RL, Tyring SK, Betts RF, McDermott MP, Pennella-Vaughan J, et al. A randomized, placebo-controlled trial of oxycodone and of gabapentin for acute pain in herpes zoster. Pain. Apr 2009;142(3):209-17. [Medline].
[Best Evidence] Irving G, Jensen M, Cramer M, Wu J, Chiang YK, Tark M, et al. Efficacy and tolerability of gastric-retentive gabapentin for the treatment of postherpetic neuralgia: results of a double-blind, randomized, placebo-controlled clinical trial. Clin J Pain. Mar-Apr 2009;25(3):185-92. [Medline].
Dworkin RH, Johnson RW, Breuer J, Gnann JW, Levin MJ, Backonja M, et al. Recommendations for the management of herpes zoster. Clin Infect Dis. Jan 1 2007;44 Suppl 1:S1-26. [Medline].
Beutner KR, Friedman DJ, Forszpaniak C, Andersen PL, Wood MJ. Valaciclovir compared with acyclovir for improved therapy for herpes zoster in immunocompetent adults. Antimicrob Agents Chemother. Jul 1995;39(7):1546-53. [Medline].
Colin J, Prisant O, Cochener B, Lescale O, Rolland B, Hoang-Xuan T. Comparison of the efficacy and safety of valaciclovir and acyclovir for the treatment of herpes zoster ophthalmicus. Ophthalmology. Aug 2000;107(8):1507-11. [Medline].
Whitley RJ, Weiss H, Gnann JW Jr, Tyring S, Mertz GJ, Pappas PG, et al. Acyclovir with and without prednisone for the treatment of herpes zoster. A randomized, placebo-controlled trial. The National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group. Ann Intern Med. Sep 1 1996;125(5):376-83. [Medline].
Tyring S, Engst R, Corriveau C, Robillard N, Trottier S, Van Slycken S, et al. Famciclovir for ophthalmic zoster: a randomised aciclovir controlled study. Br J Ophthalmol. May 2001;85(5):576-81. [Medline].
National Center for Immunization and Respiratory Diseases. Varicella Vaccine - Q&A about High Risk. Centers for Disease Control and Prevention. Available at http://www.cdc.gov/vaccines/vpd-vac/varicella/vac-faqs-clinic-highrisk.htm. Accessed December 11, 2008.
Brody MB, Moyer D. Varicella-zoster virus infection. The complex prevention-treatment picture. Postgrad Med. Jul 1997;102(1):187-90, 192-4. [Medline].
Kost RG, Straus SE. Postherpetic neuralgia--pathogenesis, treatment, and prevention. N Engl J Med. Jul 4 1996;335(1):32-42. [Medline].
Nikkels AF, Pierard GE. Recognition and treatment of shingles. Drugs. Oct 1994;48(4):528-48. [Medline].
Straus SE. Overview: the biology of varicella-zoster virus infection. Ann Neurol. 1994;35 Suppl:S4-8. [Medline].
Wareham DW, Breuer J. Herpes zoster. BMJ. June 2007;334(7605):1211-1215. [Medline].
Wood MJ. Current experience with antiviral therapy for acute herpes zoster. Ann Neurol. 1994;35 Suppl:S65-8. [Medline].
Wood MJ, Johnson RW, McKendrick MW, Taylor J, Mandal BK, Crooks J. A randomized trial of acyclovir for 7 days or 21 days with and without prednisolone for treatment of acute herpes zoster. N Engl J Med. Mar 31 1994;330(13):896-900. [Medline].
herpes zoster, shingles, zona ignea, zona serpiginosa, zoster, herpesvirus, varicella-zoster virus, VZV, VZV infection, VZV reactivation, varicella-zoster virus infection, zoster sine herpete, chickenpox, chicken pox, vesicular rash, zoster keratitis, Ramsay Hunt syndrome, herpeszosteroticus, transitory unilateral facial paralysis, postherpetic neuralgia, conjunctivitis, keratitis, corneal ulceration, iridocyclitis, glaucoma, peripheral facial nerve weakness, peripheral facial nerve palsy, myelitis, cranial nerve palsies, granulomatous angiitis, disseminated zoster, encephalitis, hepatitis, pneumonitis, tingling, burning, trigeminal neuralgia, herniated nucleus pulposus with radiculopathy, erythematous rash, meningoencephalitis, dorsal root ganglion
Richard S Krause, MD, Senior Faculty, Department of Emergency Medicine, State University of New York at Buffalo School of Medicine
Richard S Krause, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.
Jeffrey Glenn Bowman, MD, MS, Consulting Staff, Highfield MRI, Columbus, Ohio
Disclosure: Nothing to disclose.
Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment
Eric L Weiss, MD, DTM&H, Director of Stanford Travel Medicine, Medical Director of Stanford Lifeflight, Assistant Professor, Departments of Emergency Medicine and Infectious Diseases, Stanford University School of Medicine
Eric L Weiss, MD, DTM&H is a member of the following medical societies: American College of Emergency Physicians, American College of Occupational and Environmental Medicine, American Medical Association, American Society of Tropical Medicine and Hygiene, Physicians for Social Responsibility, Southeastern Surgical Congress, Southern Association for Oncology, Southern Clinical Neurological Society, and Wilderness Medical Society
Disclosure: Nothing to disclose.
John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.
Steven C Dronen, MD, FAAEM, Director of Emergency Services, Director of Chest Pain Center, Department of Emergency Medicine, Ft Sanders Sevier Medical Center
Steven C Dronen, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.