Chronic varicella-zoster virus skin lesions in patients with human immunodeficiency virus are related to decreased expression of gE and gB

The pathogenesis of chronic, verrucous varicella-zoster virus (VZV) cutaneous lesions in human immunodeficiency virus (HIV)-infected persons is unknown. It has been hypothesized that these lesions are due to an altered pattern of virus gene expression. Immediate early and late (L) gene expression in five chronic verrucous VZV lesions, four full-blown herpes zoster vesicular lesions in HIV-infected persons, and eight vesicular herpes zoster lesions in immunocompetent individuals was semiquantitatively assessed immunohistochemically using specific antibodies to the IE63, gE (L), and gB (L) proteins. All patients had evidence of IE63 expression in keratinocytes; however, gE expression was either weak or absent in keratinocytes of three verrucous lesions, and gB was either weak or absent in two. These results suggest that chronic VZV skin lesions are associated with diminished gE and gB expression. It is inferred that the VZV behavior in keratinocytes may vary from a latency-like state to a fully developed, productive infection.     

Subcutaneous implantation metastasis of a cholangiocarcinoma of the bile duct after percutaneous transhepatic biliary drainage (PTBD)

The differential diagnosis of herpes simplex and zoster may require virological confirmation, yet virus typing is not regarded as necessary in routine dermatological assessment. In an attempt to evaluate the clinical benefits of the routine detection of herpes simplex virus (HSV) and varicella zoster virus (VZV), we analysed skin swabs from 110 patients who were diagnosed at the first clinical visit as having herpes simplex (n = 45) or zoster (n = 65). Viruses were typed using the polymerase chain reaction (PCR) with the general primer pair GPHV-RU. PCR analysis showed that at the initial clinical presentation, herpes simplex in these patients was not mistaken for zoster but that zoster was incorrectly diagnosed as herpes simplex in nine cases. Thus these results suggest that initial zoster often mimics herpes simplex, hence routine PCR diagnosis of HSV and VZV or alternative rapid diagnostic approaches may be beneficial in these cases.     

Effects of age, sex, and pharmacologic agents on the biliary elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in F344 rats

It has been considered that a decline in specific cell-mediated immunity (CMI) for the varicella-zoster virus (VZV) could be responsible for a high incidence of herpes zoster in the elderly. If the strength of CMI for VZV could be increased by immunization of the elderly with a varicella vaccine, herpes zoster might be preventable. We compared the CMI for VZV (using a lymphoproliferative assay and a varicella skin test) and VZV-IgG antibodies in serum before and after 2-3 months of vaccination in 15 subjects more than 40 years old. When the CMI for VZV was measured by the lymphoproliferative assay, a stimulation index (SI) of more than 2.0 was estimated to be positive in this study. The SIs (mean +/- SD) before and after the vaccination were 2.7 +/- 1.8 and 2.7 +/- 1.9, respectively, and no significant difference was noted. On the other hand, the diameter of erythema in the varicella skin test after the vaccination became larger than that before the vaccination in the 10 of 13 subjects. In addition, serum VZV-IgG antibodies increased after vaccination in 6 of 14 subjects. There were no obvious reasons for the discrepancy in the results of the lymphoproliferative assay and the varicella skin test. However, because of the poor response indicated by the assay, only one vaccination for the elderly might not be enough to increase the CMI for VZV. The appropriate age for vaccination should also be considered. Lastly, further investigation of the CMI for VZV before and after vaccination on larger scale is required.     

Varicella zoster virus vaccine--a review

The available published data on the efficacy and safety of a live attenuated varicella vaccine is presented. The data indicate that immunosuppressed leukemic children at high risk for severe varicella can be vaccinated resulting in complete or partial immunity in most children. Vaccination of immunosuppressed children is often associated with fever and rash. There seems to be a decreased risk of herpes zoster in vaccinated leukemic children when compared with a group of naturally infected leukemic children. In order to diminish the risk of varicella zoster virus (VZV) transmission to these high-risk persons family members of these, if susceptible to varicella infection, should be immunized. Although vaccination of healthy children is highly effective and associated with a low frequency of adverse events, vaccination in this group may be questioned due to the benign course of varicella. Due to the more severe VZV-infection seen among non-immune healthy adults, it seems reasonable to offer vaccination to this group. It will, however, require extensive serological testing to identify seronegative individuals. From a theoretical point of view a booster-vaccination to the elderly population, resulting in detectable cell-mediated immunity to VZV, should reduce the risk of herpes zoster. Large placebo-controlled studies are needed to confirm if such an immunization can prevent herpes zoster in this age group.     

Comparison of primary sensitization of naive human T cells to varicella-zoster virus peptides by dendritic cells in vitro with responses elicited in vivo by varicella vaccination

Dendritic cells (DC) are potent APC during primary and secondary immune responses. The first objective of this study was to determine whether human DC mediate in vitro sensitization of naive CD4+ T cells to epitopes of the immediate early 62 (IE62) protein of varicella zoster virus (VZV). The induction of CD4+ T cell proliferative responses to eight synthetic peptides representing amino acid sequences of the VZV IE62 protein was assessed using T cells and DC from VZV-susceptible donors. The second objective was to compare in vitro responses of naive T cells with responses to VZV peptides induced in vivo after immunization with varicella vaccine. T cell proliferation was induced by three peptides, P1, P4, and P7, in 71-100% of the donors tested before and after vaccination using DC as APC. Monocytes were effective APC for VZV peptides only after immunization. Two peptides, P2 and P8, induced naive T cell proliferation less effectively and were also less immunogenic for T cells from vaccinated or naturally immune donors. T cell recognition of specific peptides was concordant between naive, DC-mediated responses, and postvaccine responses using monocytes as APC in 69% of comparisons (p = 0.05; chi2); the predictive value of a positive response to an IE62 peptide before immunization for T cell sensitization in vivo was 82%. These observations indicate that primary T cell responses detected in vitro using DC as APC may be useful to characterize the potential immunogenicity of viral protein epitopes in vivo.     

Synthesis of 2'-aminomethyl derivatives of N-(2-(phosphonomethoxy)ethyl) nucleotide analogues as potential antiviral agents

A series of purine and pyrimidine N-(2-(phosphonomethoxy)ethyl) derivatives bearing aminomethyl, (dimethylamino)methyl, morpholinomethyl, and (trimethylammonio)methyl groups at the 2'-position were synthesized. The compounds were prepared by alkylation of the heterocyclic bases with appropriately substituted (aminoalkyl)oxiranes followed by condensation of the resulting intermediates with dialkyl ((p-tolylsulfonyl)oxy)methanephosphonate and subsequent treatment of the obtained diester with bromotrimethylsilane. 9-(3-Amino-2-(phosphonomethoxy)propyl)adenine (2a) proved active against varicella zoster virus (VZV), cytomegalovirus (CMV), and Moloney murine sarcoma virus (MSV) in the concentration range of 7-35 micrograms/mL. None of the other aminoalkyl derivatives demonstrated significant antiviral activity against herpes simplex virus type 1 and 2 (HSV-1 and HSV-2), VZV, (CMV), vaccinia virus (VV), MSV, and human immunodeficiency virus type 1 and 2 (HIV-1 and HIV-2).     

Polymerase chain reaction-based assays of vitreous samples for the diagnosis of viral retinitis. Use in diagnostic dilemmas

OBJECTIVE: This study aimed to review the authors' results using polymerase chain reaction (PCR)-based assays for the diagnosis of viral retinitis. DESIGN: The study design was a retrospective case series. PARTICIPANTS: Thirty-seven patients (38 eyes) with active retinitis from whom vitreous biopsy specimens were received in the authors' laboratory for diagnostic evaluation. INTERVENTION: Vitreous biopsy specimens were evaluated with previously described PCR-based assays for cytomegalovirus (CMV), varicella zoster virus (VZV), and herpes simplex virus (HSV) DNA; clinical histories were reviewed. MAIN OUTCOME MEASURES: Laboratory findings and clinical course were measured. RESULTS: The results of the authors' assays were consistent with the long-term clinical course of each patient. Cytomegalovirus, VZV, or HSV DNA was detected in the vitreous from 24 patients. Cytomegalovirus DNA was detected in vitreous biopsy specimens from 10 patients (11 eyes). Nine patients (ten eyes) with acquired immune deficiency syndrome ultimately were diagnosed with CMV retinitis as they were followed clinically over time. Varicella zoster virus DNA was detected in vitreous biopsy specimens from eight patients; seven adult patients were ultimately diagnosed with acute retinal necrosis or progressive outer retinal necrosis. Herpes simplex virus DNA was detected in vitreous biopsy specimens from six patients; five patients had previous or subsequent herpes encephalitis. No viral DNA was detected in the vitreous from 13 patients; all were ultimately diagnosed with toxoplasmosis, syphilis, Behcet disease, fungal endophthalmitis, or idiopathic inflammation. CONCLUSIONS: These data further support the use of PCR-based assays of vitreous specimens in the diagnostic evaluation of patients with infectious retinitis.     

Polymerase chain reaction on cerebrospinal fluid for diagnosis of virus-associated opportunistic diseases of the central nervous system in HIV-infected patients

OBJECTIVE: To assess the diagnostic reliability of polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) for virus-associated opportunistic diseases of the central nervous system (CNS) in HIV-infected patients. DESIGN: CSF samples from 500 patients with HIV infection and CNS symptoms were examined by PCR. In 219 patients the PCR results were compared with CNS histological findings. METHODS: Nested PCR for detection of herpes simplex virus (HSV) type 1 or 2, varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and JC virus (JCV) DNA. Histopathological examination of CNS tissue obtained at autopsy or on brain biopsy. RESULTS: DNA of one or more viruses was found in CSF in 181 out of 500 patients (36%; HSV-1 2%, HSV-2 1%, VZV 3%, CMV 16%, EBV 12%, HHV-6 2%, and JCV 9%). Among the 219 patients with histological CNS examination, HSV-1 or 2 was detected in CSF in all six patients (100%) with HSV infection of the CNS, CMV in 37 out of 45 (82%) with CMV infection of the CNS, EBV in 35 out of 36 (97%) with primary CNS lymphoma, JCV in 28 out of 39 (72%) with progressive multifocal leukoencephalopathy. Furthermore, HSV-1 was found in one, VZV in four, CMV in three, EBV in three, HHV-6 in seven, and JCV in one patient without histological evidence of the corresponding CNS disease. CONCLUSIONS: CSF PCR has great relevance for diagnosis of virus-related opportunistic CNS diseases in HIV-infected patients as demonstrated by its high sensitivity, specificity, and the frequency of positive findings.     

The inverted repeat regions of the simian varicella virus and varicella-zoster virus genomes have a similar genetic organization

Simian varicella virus (SVV) causes a varicella-like disease in nonhuman primates. The DNA sequence and genetic organization of the inverted repeat region (RS) of the SVV genome was determined. The SVV RS is 7559 bp in size with 56% guanine+cytosine (G+C) content and includes 3 open reading frames (ORFs). The SVV RS1 ORF encodes a 1279 amino acid (aa) protein with 58 and 39% identity to the varicella-zoster virus (VZV) gene 62 and herpes simplex virus type 1 (HSV-1) ICP4 homologs, respectively. The predicted 261 aa SVV RS2 polypeptide possesses 52% identity with the VZV gene 63 homolog and 23% identity with the HSV-1 ICP22. The SVV RS3 encodes a 187 aa polypeptide with 56% and 28% identity to the VZV gene 64 and the HSV-1 US10 homologs, respectively, and includes an atypical zinc finger motif. A G+C-rich 16 base-pair (bp) sequence which is repeated 7 times and a putative SVV origin of replication were identified between the RS1 and RS2 ORFs. Comparison with the VZV RS indicates the SVV and VZV RS regions are similar in size and genetic organization.     

Infrequent detection of cytomegalovirus and Epstein-Barr virus DNA in synovial membrane of patients with rheumatoid arthritis

OBJECTIVE: To study the role of the cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus types 1 and 2 (HSV-1 and 2), varicella zoster virus (VZV), and human herpes virus 6 (HHV-6) in the etiology of rheumatoid arthritis (RA). METHODS: Polymerase chain reaction (PCR) was used to detect DNA of the different herpes viruses in synovial membranes from 31 patients with chronic RA and 14 control patients. Specific antibodies were determined by indirect immunofluorescence and ELISA. RESULTS: Out of 31 patients with RA, CMV DNA was detected in synovial membranes from 2 patients and EBV DNA was detected in synovial membranes from 2 other patients. All samples from the patients with RA were negative for DNA from HSV-1 and 2, VZV, and HHV-6. All samples from the 14 control patients were negative in all PCR assays. No statistically significant differences in IgG antibodies were found for CMV, HSV-1, VZV, and HHV-6 in patients with RA compared to controls. Higher titers of IgG antibodies against EBV viral capsid antigen were found in patients with RA, with a significance of p < 0.05. CONCLUSION: Both CMV and EBV DNA were detected in synovial membranes from 6% of the patients with RA. We cannot exclude the possibility that these viruses were associated with disease development in a minority of patients with RA.     

Varicella-zoster virus infection in children with underlying human immunodeficiency virus infection

This article describes a prospective longitudinal study of varicella-zoster virus (VZV) infections in human immunodeficiency virus (HIV)-infected children, designed to determine their natural history of VZV infection and possible effects of VZV on the progression of HIV infection. Varicella was usually not a serious acute problem, and it did not seem to precede clinical deterioration. The rate of zoster was high: 70% in children with low levels of CD4+ lymphocytes at the time of development of varicella. It is predicted that immunization with live attenuated varicella vaccine is unlikely to be deleterious to HIV-infected children. Moreover, if they are immunized when they still have relatively normal levels of CD4+ lymphocytes, they may have a lower rate of reactivation of VZV than if they were allowed to develop natural varicella when their CD4+ cell counts have fallen to low levels as a result of progressive HIV infection.     

Antibody deposits in Tzanck smears in pemphigus vulgaris

Forty-three patients, including 24 males and 19 females between 5 and 62 years of age, having pemphigus vulgaris (27), pemphigus foliaceus (1), bullous pemphigoid (3), chronic benign bullous dermatosis of childhood (2) and herpes zoster (10) were included in this study. Tzanck smears were prepared from the floor of the blisters in these patients by deroofing the bullae, and the slides were stored without fixation at room temperature for 1 to 10 days. Immunofluorescence staining was done with FITC-conjugated anti-human IgG. Twenty-one cases having pemphigus vulgaris and 1 case having pemphigus foliaceus showed bright green fluorescence on the membrane of acantholytic cells. No epithelial cells were seen in smears from bullous pemphigoid and chronic benign bullous dermatosis of childhood, whereas epithelial cells were seen in 10 cases of herpes zoster. These stained negative with anti-IgG. Storage of the prepared smears for 1-10 days did not seem to affect the results of immunofluorescence. Tzanck smears can be used as an easy substitute for skin/mucosal biopsy for the direct immunofluorescence test.     

Postherpetic neuralgia in immunocompetent elderly people

The most menacing complication of herpes zoster in immunocompetent elderly people is chronic pain or postherpetic neuralgia (PHN). The cardinal epidemiological feature of PHN is its striking relationship to aging. Among zoster patients over 60 years old, estimates of the occurrence of PHN, defined as pain 1 month after rash onset, vary from 27 to 68%. The pathogenesis of PHN is incompletely understood but seems to involve varicella-zoster virus (VZV)-induced damage of peripheral afferent neurons and resultant changes in central afferent neurons and efferent pain-modulating neurons. PHN improves over time in many elderly patients, but an unfortunate subset experience of debilitating pain lasts for years. They experience constant and/or intermittent spontaneous pain and stimulus-evoked pain such as allodynia or hyperpathia. The outcomes of this pain include fatigue, sleep disturbance, anorexia, depression, social withdrawal, impaired activities of daily living and profound lowering of quality of life. The management of PHN is hampered by two problems: (1) a uniformly effective treatment for PHN is not available (although tricyclic antidepressants, local or regional anaesthetics, capsaicin, opiates, anticonvulsants and physical therapies are sometimes useful); and (2) early antiviral therapy of zoster may be ineffective in preventing PHN, partly related to the fact that days of VZV replication and neuronal destruction have occurred by the time the patient reaches the doctor. A potential solution to the problem of PHN is the vaccination of elderly persons with the varicella vaccine to prevent or attenuate zoster or PHN.     

Transdermal application of 10% lidocaine-gel for management of pain associated with herpes zoster

We have developed transdermally applicable 10% lidocaine aqueous gel containing an absorption promoter and applied it for 15 patients suffering from severe pain in acute or subacute phase of herpes zoster. The patients, consisting of 7 males and 8 females with a mean age 58.5 +/- 13.0 (SD) yrs, had skin eruptions of herpes zoster for the past 2 months. Lidocaine-gel was applied locally to the diseased skin with or without an occlusive dressing. In 14 of the 15 patients (93%), a remarkable reduction of pain (below 10% of pretreatment level) was obtained after 9.9 +/- 5.6 (SD) times of lidocaine-gel treatments. There was no adverse systemic reactions or local skin damages. None of them developed post-herpetic neuralgia. The lidocaine-gel treatment appears to be very useful for reduction of pain associated with acute or subacute phase of herpes zoster.     

Epidemiology of encephalitis in children. A prospective multicentre study

We found 175 cases with acute encephalitis in a population of 791,712 children aged 1 month-15 years during a 2-year surveillance period in 1993-1994. The overall incidence was 10.5/100,000 child-years with the highest figure in children < 1 year of age, 18.4/100,000 child-years. The microbial diagnosis was considered proven or suggested in 110 cases (63%); varicella zoster, respiratory and enteroviruses comprised 61% of these, and adeno, Epstein Barr-, herpes simplex and rota viruses comprised 5% each. A clearcut change seems to have occurred in the aetiology of encephalitis. Mumps, measles, and rubella virus associated encephalitides have been almost eliminated. Varicella zoster, respiratory, and enteroviruses have increased in frequency and occur in younger age groups. New causes were identified, especially Chlamydia pneumoniae and HHV-6. Our data should assist in making a specific diagnosis and defining appropriate antimicrobial therapy. CONCLUSIONS: The spectrum of encephalitis in children has changed due to vaccination programs. The incidence, however, appears to be about the same due to increasing frequency of other associated old and new microbes.     

High incidence of breakthrough varicella observed in healthy Japanese children immunized with live attenuated varicella vaccine (Oka strain)

In order to know the rate of occurrence of varicella among vaccinees (breakthrough varicella: BV), questionnaire postcards were sent to 593 healthy children who had received varicella vaccine (Oka strain) from March 1987 to December 1989. The questionnaire survey was repeated once a year until January 1996. The annual attack rate from the 1st to 3rd questionnaire was approximately 12%: however, from the 5th to 8th one it was 1-4%. To February 1996, the cumulative attack rate was 157/459 (34.2%). This rate was comparable to that among vaccinees who had confirmed seroconversion; namely, 51/132 (38.6%). These rates are much higher than those reported by other authors. All BV cases were clinically mild; even subjects who had received the vaccine 7 years prior to the disease showed mild symptoms. The high incidence may be partly explained by the regional epidemiology of varicella. The decrease in annual incidence with time after vaccination may be due to the following reasons: some vaccinees remained free from BV owing to reinforcement of their immunity from subclinical infection of varicella-zoster virus (VZV) and others from diminution of opportunity for exposure to VZV with increasing age. Varicella vaccine seems to be effective in modifying the symptoms of varicella, but not potent enough in protecting from VZV infection.     

Urinary retention due to herpes virus infections

Urinary retention is uncommon in patients with herpes zoster and anogenital herpes simplex. Seven patients (four men, three women) with a mean age of 68.1 years (range, 35-84) with urinary retention due to herpes zoster (n = 6) or anogenital herpes simplex (n = 1) were studied. Six patients had unilateral skin eruption in the saddle area (S2-4 dermatome) and one patient with herpes zoster had a skin lesion in the L4-5 dermatome. All patients had detrusor areflexia without bladder sensation, and two of them had inactive external sphincter on electromyography at presentation. Clean intermittent catheterization was performed, and voiding function was recovered in 4-6 weeks (average, 5.4) in all patients. Urodynamic study was repeated after recovery of micturition in three patients, and they returned to normal on cystometrography and external sphincter electromyography. Acute urinary retention associated with anogenital herpes infection has been thought to occur when the meninges or sacral spinal ganglia were involved, and, in conclusion, this condition may be considered to be reversible.     

(R)-(-)- and (S)-(+)-Synadenol: synthesis, absolute configuration, and enantioselectivity of antiviral effect

Synthesis of (R)-(-)- and (S)-(+)-synadenol (1a and 2a, 95-96% ee) is described. Racemic synadenol (1a + 2a) was deaminated with adenosine deaminase to give (R)-(-)-synadenol (1a) and (S)-(+)-hypoxanthine derivative 5. Acetylation of the latter compound gave acetate 6. Reaction with N, N-dimethylchloromethyleneammonium chloride led to 6-chloropurine derivative 7. Ammonolysis furnished (S)-(+)-synadenol (2a). Absolute configuration of 1a was established by two methods: (i) synthesis from (R)-methylenecyclopropanecarboxylic acid (8) and (ii) X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. Racemic methylenecyclopropanecarboxylic acid (10) was resolved by a modification of the described procedure. The R-enantiomer 8 was converted to ethyl ester 13 which was brominated to give vicinal dibromides 14. Reduction with diisobutylaluminum hydride then furnished alcohol 15 which was acetylated to the corresponding acetate 16. Alkylation-elimination procedure of adenine with 16 yielded acetates 17 and 18. Deprotection with ammonia afforded a mixture of Z- and E-isomers 1a and 19 of the R-configuration. Comparison with products 1a and 2a by chiral HPLC established the R-configuration of (-)-synadenol (1a). These results were confirmed by X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. The latter forms a pseudosymmetric dimer with adenine-adenine base pairing in the lattice with the nucleobase in an anti-like conformation. Enantiomers 1a and 2a exhibit varied enantioselectivity toward different viruses. Both enantiomers are equipotent against human cytomegalovirus (HCMV) and varicella zoster virus (VZV). The S-enantiomer 2a is somewhat more effective than R-enantiomer 1a in herpes simplex virus 1 and 2 (HSV-1 and HSV-2) assays. By contrast, enantioselectivity of antiviral effect is reversed in Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-1) assays where the R-enantiomer 1a is preferred. In these assays, the S-enantiomer 2a is less effective (EBV) or devoid of activity (HIV-1).     

A retrospective study of the clinical presentation and outcome of herpes zoster in a tertiary dermatology outpatient referral clinic

BACKGROUND: This is a retrospective study of the epidemiology and morbidity of herpes zoster and the risk factors for herpes zoster morbidity in Singapore. RESULTS: The mean age of 164 patients with herpes zoster seen at our dermatology clinic between January 1994 and December 1995 was 48.8 years, with a sex ratio of 1:1. The common presenting symptoms were pain (90%), feelings of helplessness and depression (20%), and flu-like symptoms (12%). The commonest prodromes were pain (41%), itching (27%), and paresthesia (12%). Prodromal pain was more frequently experienced by patients aged more than 50 years (42%) than by patients aged less than 30 years (25%). The thoracic (45%) and cervical (23%) dermatomes were the most commonly affected in all age groups. There was no statistically significant difference in the frequency of dermatomal distribution among the different age groups and between the sexes. Pain was experienced by almost all (95%) patients during the course of their disease. It tended to be more severe in older patients. Burning (26%), stabbing (15%), and shooting (15%) pain were the most common types experienced. Post-herpetic neuralgia was significantly more common in older patients. The prevalence of post-herpetic neuralgia decreased over time in all age groups. A higher proportion of older patients (more than 50 years of age) (20%) suffered from post-herpetic neuralgia compared with younger patients (less than 30 years of age) (7%) (not significant). Patients in all age groups considered acute pain (46%) and persistent pain (25%) to be their most unbearable symptoms during the course of herpes zoster. The most significant problems caused by herpes zoster pain were insomnia (25%), misery (feeling helpless and depressed) (20%), limitation of movement (9%), and inability to continue work (8%). Insomnia was significantly more commonly experienced by patients more than 50 years of age (36%) than those less than 30 years of age (P = 0.026). Few patients (9%) consulted their general practitioner (GP) during the prodrome or on the day of appearance of skin eruptions. Most patients (45%) consulted their GP within the first 3 days of the onset of skin eruptions; 33% sought treatment more than 3 days after the appearance of zoster symptoms. Only 30% of patients were willing to pay more than S$200 for antiviral therapy. Most (43%) were only prepared to pay for antiviral treatment if it cost less than S$200. The most important features the patients wished to derive from antiviral therapy were a shortening of the duration of skin lesions (55%) and a reduction in the severity of pain (acute and chronic) (30%). CONCLUSIONS: Our study indicated that older patients (aged more than 50 years) were at a higher risk of developing post-herpetic neuralgia. They were also more likely to suffer morbidity, e.g. insomnia. There is a need to educate patients at risk to identify the prodrome and skin eruptions of herpes zoster so that early antiviral therapy can be considered.