Distribution of varicella-zoster virus gpI and gpII and corresponding genome sequences in the skin

Conditions and Factors That Raise the Risk of Developing Skin Lesions After Shingles

Objective

To understand the situation and risk factors of skin lesions following the eruption of shingles.

Methods

We selected 275 patients with shingles who had been diagnosed and treated in the Dermatology Department of Changshu No. 1 People's Hospital between July 2017 and March 2022. Age, gender, skin lesion site, skin lesion type, prodromal pain, history of diabetes, history of hypertension, history of other immune diseases, as well as other pertinent clinical data, were collected. The severity and pain of patients with severe shingles were evaluated, and their fasting blood sugar and plasma albumin were measured for routine antiviral treatment. They were followed up 6 months-the types of skin lesions and pertinent clinical data were compared, and the risk factors for skin lesions were analyzed.

Results

There were no statistically significant differences in gender, age, or site among the different types of skin lesions (P > 0.05). The severity of skin lesions, acute pain, history of diabetes, history of scars, low immune function, combined with hypoproteinemia, squeezing and stripping behavior, and post-herpetic neuralgia (PHN) were significantly associated with skin lesions (P < 0.05). The results of multivariate analysis showed that: age ≥60 years old, severe skin injury combined with diabetes, low immune function, scar history, squeezing and stripping were independent risk factors for the development of skin lesions due to shingles.

Conclusion

There is no significant difference in age, gender, site, or other characteristics between the types of skin lesions due to shingles. The independent risk factors of skin lesions due to shingles are old age, severe rash, history of scars, diabetes, low immunity, squeezing, and peeling.

Incidence of and Risk Factors for Cutaneous Scarring after Herpes Zoster

BACKGROUND

About 20% of children have cutaneous scars following chickenpox. In contrast, skin scars are not often reported after herpes zoster (HZ). Risk factors for post-HZ scarring remain undetermined.

OBJECTIVE

Our objective was to prospectively study the incidence of and risk factors for post-HZ scarring.

METHODS

This was a 3-year prospective study of patients with HZ attending a tertiary university hospital. Baseline data, including age, sex, immunosuppression, prior history of scarring, severity and extension of HZ, afflicted HZ dermatome, and antiviral treatment received, were recorded. At 1 month after the HZ skin lesions had healed, patients were screened for skin scars at the prior HZ site. These patients were followed every 2 months for 6 months.

RESULTS

At 6 months, 11 (9.7%) of 113 HZ patients still had post-HZ scarring (fair-skinned patients: hypopigmented [n = 3], hyperpigmented [n = 2], atrophic cicatricial [n = 3], and hypertrophic cicatricial [n = 1]; dark-skinned patients: severe hyperpigmented hypertrophic scarring [n = 2]). HZ was extensive and severe in all cases. Nine of the 11 patients were immunocompromised. Three cases had a history of hypertrophic/keloid scarring but no post-varicella scars. The most frequent location was the trunk (n = 5), followed by the cervical region (n = 3) and the face (n = 3). Given the study setting, it is possible that immunocompromized patients with severe HZ were overrepresented in this study.

CONCLUSIONS

Scarring after HZ is probably overlooked. The principal risk factors seem to be severe HZ and immunosuppression. Hence, prompt instigation of antiviral treatment for HZ and HZ vaccination could help reduce the incidence of post-HZ scarring.

Viral load and antibody boosting following herpes zoster diagnosis

BACKGROUND

Acute varicella zoster virus (VZV) replication in shingles is accompanied by VZV antibody boosting. It is unclear whether persisting virus shedding affects antibody levels.

OBJECTIVES

To investigate the relationship between VZV viral load and antibody titres in shingles patients during six months following diagnosis and assess whether VZV antibody titre could discriminate patients with recent shingles from healthy population controls.

STUDY DESIGN

A prospective study of 63 patients with active zoster. Blood samples were collected at baseline, one, three and six months to measure VZV DNA and IgG antibody titre. We compared VZV antibody titres of zoster patients and 441 controls.

RESULTS

In acute zoster, viral load was highest at baseline and declined gradually over the following six months. Mean antibody titres rose fourfold, peaking at one month and remaining above baseline levels throughout the study. Antibody levels at one, three and six months after zoster were moderately correlated with baseline but not subsequent viral load. Regarding use of antibody titres to identify recent shingles, to achieve 80% sensitivity, specificity would be 23.4%, 67.7%, 64.8% and 52.6%, at baseline, visit 2, 3 and 4 respectively, whilst to achieve 80% specificity, sensitivity would be 28.3%, 66.1%, 52.6%, 38.6%, at baseline, visit 2, 3 and 4 respectively.

CONCLUSIONS

Clinical VZV reactivation boosted VZV antibody levels and the level of boosting was dependent upon baseline viral replication. While antibody titres could discriminate patients with shingles 1-6 months earlier from blood donor controls, there was a large trade-off between sensitivity and specificity.

European consensus-based (S2k) Guideline on the Management of Herpes Zoster - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV), Part 1: Diagnosis

Herpes zoster (HZ, shingles) is a frequent medical condition which may severely impact the quality of life of affected patients. Different therapeutic approaches to treat acute HZ are available. The aim of this European project was the elaboration of a consensus-based guideline on the management of patients who present with HZ, considering different patient populations and different localizations. This interdisciplinary guideline aims at an improvement of the outcomes of the acute HZ management concerning disease duration, acute pain and quality of life of the affected patients and at a reduction of the incidence of postherpetic neuralgia and other complications. The guideline development followed a structured and predefined process, considering the quality criteria for guidelines development as suggested by the AGREE II instrument. The steering group was responsible for the planning and the organization of the guideline development process (Division of Evidence based Medicine, dEBM). The expert panel was nominated by virtue of clinical expertise and/or scientific experience and included experts from the fields of dermatology, virology/infectiology, ophthalmology, otolaryngology, neurology and anaesthesiology. Recommendations for clinical practice were formally consented during the consensus conference, explicitly considering different relevant aspects. The guideline was approved by the commissioning societies after an extensive internal and external review process. In this first part of the guideline, diagnostic means have been evaluated. The expert panel formally consented recommendations for the management of patients with (suspected) HZ, referring to the assessment of HZ patients, considering various specific clinical situations. Users of the guideline must carefully check whether the recommendations are appropriate for the context of intended application. In the setting of an international guideline, it is generally important to consider different national approaches and legal circumstances with regard to the regulatory approval, availability and reimbursement of diagnostic and therapeutic interventions.

Cell-mediated immune responses to a varicella-zoster virus glycoprotein E vaccine using both a TLR agonist and QS21 in mice

Lack of adequate cell-mediated immunity (CMI) to varicella-zoster virus (VZV) has been associated with higher risks of developing herpes zoster (HZ) and associated post-herpetic neuralgia (PHN), and is of particular concern for older and immunocompromised individuals. Thus, the development of an effective HZ vaccine with a clinically acceptable safety profile that is capable of addressing decreased immunity would be highly desirable. In this study we compared the immunogenicity of different vaccine formulations containing VZV glycoprotein E (gE), an important target for CMI and antibody responses, in a VZV-primed mouse model. The formulations included recombinant gE, either unadjuvanted, or combined with aluminium salt or an Adjuvant System (AS01 or AS02), and CMI was used as the primary immunological endpoint. All adjuvanted vaccines induced gE- and/or VZV-specific CD4(+) T cell and antibody responses. A formulation of gE with an Adjuvant System containing the immunostimulants QS21 and 3-O-desacyl-4'-monophosphoryl lipid A (MPL) was shown to be more immunogenic than gE with aluminium salt or unadjuvanted gE (gE/saline). Both immunostimulants were shown to act synergistically in enhancing CMI responses. Formulations with AS01 elicited high frequencies of CD4(+) T cells producing IFN-γ and IL-2. These responses were dose-dependent with respect to both antigen and adjuvant. The gE/AS01(B) candidate vaccine induced higher frequencies of CD4(+) T cells producing IL-2 and/or IFN-γ than all other gE/AS01 formulations, supporting its use for clinical evaluations.

Viruses and Langerhans cells

Langerhans cells (LCs) are the resident dendritic cells (DCs) of epidermis in human mucosal stratified squamous epithelium and the skin. A phenotypically similar DC has recently been discovered as a minor population in the murine dermis. In epidermis, LCs function as sentinel antigen-presenting cells that can capture invading viruses such as herpes simplex virus (HSV), varicella-zoster virus (VZV) and human immunodeficiency virus (HIV). This interaction between LCs and viruses results in highly variable responses, depending on the virus as discussed in this review. For example, HSV induces apoptosis in LCs but HIV does not. LCs seem to be the first in a complex chain of antigen presentation to T cells in lymph nodes for HSV and possibly VZV, or they transport virus to T cells, as described for HIV and maybe VZV. Together with epidermal keratinocytes they may also have a role in the initial innate immune response at the site of infection in the epidermis, although this is not fully known. The full spectrum of biological responses of LCs even to these viruses has yet to be understood and will require complementary studies in human LCs in vitro and in murine models in vivo.

Impact of varicella-zoster virus on dendritic cell subsets in human skin during natural infection

Varicella-zoster virus (VZV) causes varicella and herpes zoster, diseases characterized by distinct cutaneous rashes. Dendritic cells (DC) are essential for inducing antiviral immune responses; however, the contribution of DC subsets to immune control during natural cutaneous VZV infection has not been investigated. Immunostaining showed that compared to normal skin, the proportion of cells expressing DC-SIGN (a dermal DC marker) or DC-LAMP and CD83 (mature DC markers) were not significantly altered in infected skin. In contrast, the frequency of Langerhans cells was significantly decreased in VZV-infected skin, whereas there was an influx of plasmacytoid DC, a potent secretor of type I interferon (IFN). Langerhans cells and plasmacytoid DC in infected skin were closely associated with VZV antigen-positive cells, and some Langerhans cells and plasmacytoid DC were VZV antigen positive. To extend these in vivo observations, both plasmacytoid DC (PDC) isolated from human blood and Langerhans cells derived from MUTZ-3 cells were shown to be permissive to VZV infection. In VZV-infected PDC cultures, significant induction of alpha IFN (IFN-alpha) did not occur, indicating the VZV inhibits the capacity of PDC to induce expression of this host defense cytokine. This study defines changes in the response of DC which occur during cutaneous VZV infection and implicates infection of DC subtypes in VZV pathogenesis.

Occult herpes simplex virus colonization of bullous dermatitides

BACKGROUND

Acantholytic disorders, including pemphigus vulgaris, chronic benign familial pemphigus (Hailey-Hailey disease, superficial pemphigus), Darier disease, and Grover transient acantholytic dermatosis, as well as other vesiculo-bullous disorders, including bullous pemphigoid, epidermolysis bullosa, and atopic dermatitis, are prone to florid infections by herpes simplex virus (HSV)-I and -II, and, more rarely, by varicella-zoster virus (VZV). As these infections are difficult to recognize clinically and histologically, their frequency remains unknown. A possible occult viral colonization has never been documented in these disorders. The manner in which the primary bullous disorders are contaminated by herpesviridae remains unclear.

OBJECTIVE

To retrospectively assess the possible presence of HSV and VZV in a series of biopsies of acantholytic disorders and bullous pemphigoid.

METHOD

The typical alpha-herpesviridae-related cytopathic signs were searched for by conventional microscopy in skin biopsies of patients with bullous pemphigoid (n = 20), pemphigus vulgaris (n = 19), Darier disease (n = 18), chronic benign familial pemphigus (n = 3), and Grover transient acantholytic dermatosis (n = 3). Immunohistochemistry (IHC) targeted specific HSV-I, HSV-II, and VZV antigens. Polymerase chain reaction (PCR) was used for detecting HSV- and VZV-specific DNA sequences.

RESULTS

No cytopathic signs suggestive of HSV or VZV infection were detected. However, IHC revealed HSV antigens in Darier disease (1/18, HSV-I), Grover transient acantholytic dermatosis (1/3, HSV-I), pemphigus vulgaris (1/19, HSV-I), and bullous pemphigoid (2/20, HSV-I and HSV-II). In these IHC-positive cases, PCR amplified specific HSV primers in Darier disease (1/18), pemphigus vulgaris (1/19), and bullous pemphigoid (1/20). VZV antigens and nucleic acids were never identified. The HSV antigens were nearly always restricted to the upper part of the granular layer and thus differed from the usual HSV distribution during cutaneous infection. Negative and positive controls yielded consistently positive and negative results, respectively.

CONCLUSION

This report shows for the first time that clinically and histologically occult HSV colonization may occur in Darier disease, Grover transient acantholytic disease, pemphigus vulgaris, and bullous pemphigoid. Given the frequent use of immunosuppressive treatments for primary bullous disorders, greater awareness of HSV colonization and infection is recommended in these patients.

Absence of intercellular adhesion molecule 1 expression in varicella zoster virus-infected keratinocytes during herpes zoster: another immune evasion strategy?

Downregulation of major histocompatibility complex (MHC) class I, MHC-II, and intercellular adhesion molecule 1 (ICAM-1) expression in infected cell lines allows some viruses to escape host immunity. In skin lesions of varicella zoster virus (VZV), MHC-II transcripts were demonstrated in keratinocytes around vesicles, but not in VZV-infected cells. Whether other immunoevasive mechanisms are present during herpes zoster (HZ) is not yet elucidated. The aim of the study was to disclose the temporal immunohistochemical expression of immune escape mechanisms during HZ. Sequential skin biopsies were performed in 5 HZ patients. VZV IE63, CD1a, CD3, CD4, CD8, CD56, CD68, L1, HLA-DR, HLA-ABC, interleukin (IL)-6, IL-10, interferon gamma (IFNgamma), tumor necrosis factor alpha (TNFalpha), and ICAM-1 expressions were assessed on frozen sections using immunohistochemistry. Controls consisted of normal skin, herpes simplex virus (HSV) skin infections, and other distinct bullous skin diseases. HLA-DR and ICAM-1 expressions were not observed in VZV- and HSV-infected keratinocytes, contrasting with their upregulation in the surrounding epidermis and inside nonviral blisters. However, HLA-ABC expressions were not inhibited in VZV-infected keratinocytes. Furthermore, the CD4/CD8 ratio remained unmodified during the infection evolution, and this ratio was variable among patients. Increased IFNgamma, TNFalpha, and IL-6 expressions were present, but IL-10 expression only increased in later stages. In contrast to in vitro MHC-I and MHC-II downregulation, VZV infection is related to MHC-II but not MHC-I expression on infected keratinocytes. The absence of ICAM-1 expression on infected keratinocytes may reduce their antigen presentation capacities to LFA-1 ligand-bearing T cells. This may represent another VZV-associated immune escape mechanism. Increased IFNgamma, TNFalpha, and IL-6 expressions suggest a TH1 profile.

Atypical recurrent varicella in 4 patients with hemopathies

Relapsing varicella may occur in children with HIV infection and more rarely in younger adults. Our aim was to report unusual clinical, histologic, and virologic aspects of 4 elderly patients with malignant hemopathies who had an unusual form of recurrent varicella develop. Conventional microscopy, immunohistochemistry, and in situ hybridization were applied to smears and skin biopsy specimens. The patients presented a few dozen, scattered, large, papulovesicular lesions with central crusting. No zoster-associated pain or dermatomal distribution of the lesions was noted. Conventional microscopy revealed vascular changes and epidermal alterations typical for alpha-herpes virus infection. The varicella zoster virus major viral envelope glycoproteins gE and gB, and the immediate-early varicella zoster virus IE63 protein and the corresponding genome sequence for gE were detected on Tzanck smears; they were localized in endothelial cells and keratinocytes on skin biopsy specimens. The varicella zoster virus infection in endothelial cells, the vascular involvement, and the widespread distribution of the lesions suggest that the reported eruptions are vascular rather than neural in origin. These findings invalidate the diagnosis of herpes zoster but strongly support the diagnosis of recurrent varicella in an indolent and yet unreported presentation. Furthermore, these eruptions differ from relapsing varicella in children and young adults by the age of the patients, the paucity of clinical lesions, the larger diameter of the lesions and their peculiar clinical aspect, the significantly longer time interval between primary varicella and the recurrence, the prolonged healing time of the lesions, their mild disease course, and the fact that all the lesions are in the same stage of development.

Varicella-zoster virus proteins in skin lesions: implications for a novel role of ORF29p in chickenpox

Skin biopsy samples from varicella-zoster virus (VZV)-infected patients examined by immunohistochemistry demonstrated VZV replication in nonepithelial cell types. ORF29p, a nonstructural nuclear protein, was found in nerves of two of six patients with chickenpox. In tissue culture, ORF29p was secreted by VZV-infected fibroblasts. Extracellular ORF29p can be taken up through endocytosis by human neurons, implying a novel role for this protein in pathogenesis.

Shingles developing within recent surgical scars

Occurrence of varicella and recurrence of herpes simplex on traumatized sites of the skin are well-described events. By contrast, herpes zoster occurring specifically at the site of previously injured skin has not yet been reported. Two patients are presented who developed shingles limited to skin on and around recent surgical scars. Varicella zoster virus was identified using immunohistochemistry on skin biopsy specimens and Tzanck smears. We suspect that the occurrence of herpes zoster involving surgical scars is usually misdiagnosed and therefore unrecognized. Whether shingles adjacent to scars represents a coincidental event or is specifically triggered by local injury is unknown.

Varicella-zoster virus immune evasion

CD4+ and CD8+ T cells play dual roles in varicella-zoster virus (VZV) pathogenesis. The first role is to deliver the virus to cutaneous sites during primary VZV infection, permitting replication at these sites and the successful transmission of the virus to other susceptible individuals. The second contribution of T cells is to provide the critical antigen-specific adaptive immunity needed to stop viral replication and maintain VZV latency in sensory ganglia. The equilibrium between VZV and the host can be predicted to be served by immune evasion mechanisms in at least two important ways, including the facilitation of cell-associated viremia during primary VZV infection and silent persistence in dorsal root ganglia. Interference with antigen presentation by MHC class I downregulation may be expected to play a role in both circumstances. Transient interference with MHC class II expression in varicella skin lesions should facilitate local replication and transmission. In addition, when VZV reactivates, the capacity of viral gene products to block the upregulation of MHC class II expression triggered by interferon-gamma should permit a sufficient period of viral replication to cause the lesions of herpes zoster, despite the presence of VZV-specific T cells, and to allow transmission of the virus to susceptible individuals. Although the effort is at an early stage compared to studies of other viral pathogens, identifying the VZV gene products that exert these effects and their mechanisms of interference has the potential to reveal novel aspects of MHC class I and class II antigen processing and presentation.

Characterization of viremia at different stages of varicella-zoster virus infection

Varicella-zoster virus (VZV) viremia at different stages of infection was characterized. Different approaches were used, polymerase chain reaction (PCR), isothermal transcription based nucleic acid amplification (NASBA), and immunofluorescence to describe and quantitate viral infection of peripheral blood mononuclear cells (PBMC). In patients with acute varicella 200 to 5,000 copies of the viral genome in every 150,000 PBMC were found with quantitative competitive PCR (QCPCR). With NASBA, viral transcriptional activity was detected in these cells. RNA transcribed from the immediate early gene IE 63 as well as from the late gene 68 were found, indicating a productive infection. Glycoprotein gE specific immunofluorescence visualized by confocal laser scanning microscopy revealed that only 1 in 10,000 to 100,000 PBMC was infected. T and B lymphocytes as well as monocytes expressed viral protein on their surface. Similar results were obtained with PBMC from immunocompetent zoster patients. In some cases a transient viremia was found shortly after the onset of rash, although the viral load seemed to be lower than in patients with varicella. Examination of blood samples from 16 persons with postherpetic neuralgia (PHN) signs of viral replication in PBMC were not detected. In conclusion, the data suggest that VZV viremia is a frequent event in patients with varicella and zoster, but not in those with postherpetic neuralgia. Moreover, the results indicated that subclinical reactivations occur both in immunocompromised and immunocompetent individuals.

In situ hybridization detection of varicella zoster virus in paraffin-embedded skin biopsy samples

BACKGROUND

When virologic and molecular diagnostic techniques are unavailable, the diagnosis of varicella zoster virus (VZV) infection depends on clinical criteria and histologic evaluation of skin biopsy specimens or Tzank preparations. These methods can misdiagnose chickenpox and zoster, particularly when the clinical manifestations are atypical.

OBJECTIVE

To improve diagnosis in these settings, we developed an in situ hybridization technique for the detection of VZV utilizing a fluorescein-labeled oligonucleotide probe visualized with anti-fluorescein alkaline phosphatase-conjugated antibody.

STUDY DESIGN

We retrospectively examined 26 paraffin-embedded skin biopsy specimens with histologic features consistent with VZV or herpes simplex virus (HSV) infection and 11 control cases by in situ hybridization. In situ hybridization for VZV and HSV-1 was compared with polymerase chain reaction (PCR) for VZV and HSV-1 and clinical and histologic examination.

RESULTS

Thirteen of the 26 study cases and two of the 11 control cases were positive for VZV by in situ hybridization. When compared with PCR, in situ hybridization was 92% sensitive and 88% specific. When compared with clinical diagnosis, in situ hybridization was 86% sensitive and 87% specific. All cases of chickenpox had VZV-positive inflammatory cells in the dermis but this finding was less frequent among the cases of zoster.

CONCLUSIONS

This in situ hybridization technique is a sensitive and specific method for the diagnosis of VZV in skin lesions that is applicable to most histopathology laboratory settings. In addition, in situ hybridization reveals individual infected cells and may provide insight into the pathogenesis of VZV skin infection.

Hair follicle involvement in herpes zoster: pathway of viral spread from ganglia to skin

Herpes zoster is caused by reactivation of varicella-zoster virus (VZV) persisting in dorsal root or trigeminal ganglia. To clarify the pathway of viral spread from the ganglia to skin, 16 biopsy specimens of early skin lesions of herpes zoster obtained from the face and trunk of 13 patients were studied histologically and immunohistochemically using monoclonal antibodies to the structural proteins of VZV. VZV-infected cells were detected in the hair follicles in 10 of the 16 specimens and in the epidermis in 2 specimens. Infected cells were localized in the isthmus of every involved follicle (12/12), frequently in the stem (8/10) and infundibulum (6/10), and never in the bulb. The high frequency of follicular involvement in herpes zoster suggests that VZV spreads to the area of skin innervated by myelinated nerves, which end around the isthmus of hair follicles and sebaceous glands.

Distribution of varicella zoster virus and herpes simplex virus in disseminated fatal infections

AIMS

To study the cutaneous and visceral distribution of herpes simplex virus (HSV) and varicella zoster virus (VZV) in fatal infections.

METHODS

Standard histology, immunohistochemistry (monoclonal antibodies VL8 and VL2 and polyclonal antibody IE63 directed against VZV; monoclonal antibodies IBD4 and HH2 and polyclonal antibodies directed against HSVI and HSVII) and in situ hybridisation (anti-HSV and anti-VZV probes) were applied to formalin fixed, paraffin wax sections.

RESULTS

On histological examination, Herpesviridae infection was evident in various organs including the lungs, liver and skin. In addition, immunohistochemistry and in situ hybridisation revealed the presence of HSV and VZV antigens and nucleic acids in several cell types and tissues showing no cytopathological alterations suggestive of Herpesviridae infection. The organs with histological evidence of infection also contained VZV or HSV antigens and their genes.

CONCLUSIONS

These findings suggest that organ failure in disseminated VZV and HSV infections is primarily caused by HSV or VZV induced cell damage and lysis. They also indicate that immunohistochemistry and in situ hybridisation can provide an accurate, type-specific diagnosis on formalin fixed, paraffin wax embedded tissue even when classic histological and cytological characteristics are lacking.

Immunohistochemical identification of varicella-zoster virus gene 63-encoded protein (IE63) and late (gE) protein on smears and cutaneous biopsies: implications for diagnostic use

Early and specific recognition of varicella zoster virus (VZV) infection is of vital concern in immunocompromised patients. The aim of this study was to compare the diagnostic accuracy of histochemical and immunohistochemical identification of the VZV ORF63 encoded protein (IE63) and of the VZV late protein gE on smears and formalin-fixed paraffin-embedded skin sections taken from lesions clinically diagnosed as varicella (n = 15) and herpes zoster (n = 51). Microscopic examinations of Tzanck smears and skin sections yielded a diagnostic accuracy of Herpesviridae infections in 66.7% (10/15) and 92.3% (12/13) of varicella, and 74.4% (29/39) and 87.8% (43/49) of herpes zoster, respectively. Immunohistochemistry applied to varicella provided a type-specific virus diagnostic accuracy of 86.7% (13/15; IE63) and 100% (15/15; gE) on smears, and of 92.3% for both VZV proteins on skin sections. In herpes zoster, the diagnostic accuracy of immunohistochemistry reached 92.3% (36/39; IE63) and 94.9% (37/39; gE) on smears, and 91.7% (44/48; IE63) and 91.8% (45/49; gE) on skin sections. These findings indicate that the immunohistochemical detection of IE63 and gE on both smears and skin sections yields a higher specificity and sensitivity than standard microscopic assessments.

Recognition and treatment of shingles

Varicella zoster virus (VZV) is responsible for a primary infection (varicella) followed by a latency, eventually resulting in herpes zoster (shingles). The replication cycle of VZV is normally interrupted after varicella. Consequently, VZV remains dormant in the organism. Reactivation occurs after viraemia, and the development of tissue alterations (skin and viscera) depends on the immunological status of the patient. Diagnosis of herpes zoster relies on clinical recognition and cytological and histological evaluations combined with immunohistochemistry and molecular biology techniques. Treatment of herpes zoster primarily relies upon antiviral drugs and incidentally on immunomodulating agents, specific immunoglobulins, antimicrobial agents, antiviral enzymes and corticosteroids. Drugs with a clinically relevant activity against varicella zoster virus infections include aciclovir, adenosine monophosphate, bromodeoxyuridine, desciclovir, fiacitabine, idoxuridine, interferon-alpha and vidarabine. Among them, aciclovir appears to be a first-line agent. Its efficacy has been well established by many clinical studies. Promising drugs for the future include famciclovir, penciclovir, valaciclovir and other molecules currently under investigation. Recent and promising improvements in antiviral drug development may increase patient compliance, cost-benefit ratios and therapeutic efficacy.