Tests for Detecting Herpes Simplex Virus and Varicellazoster Virus Infections

Diagnostic Methods and Management Strategies of Herpes Simplex and Herpes Zoster Infections

Herpesviruses are medium-sized double-stranded DNA viruses. Of more than 80 herpesviruses identified, only 9 human herpesviruses have been found to cause infection in humans. These include herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), human cyto-megalovirus (HCMV), Epstein-Barr virus (EBV), and human herpesvirus (HHV-6A, HHV-6B, HHV-7, HHV-8). HSV-1, HSV-2, and VZV can be problematic given their characteristic neurotropism which is the ability to invade via fusion of its plasma membrane and reside within neural tissue. HSV and VZV primarily infect mucocutaneous surfaces and remain latent in the dorsal root ganglia for a host's entire life. Reactivation causes either asymptomatic shedding of virus or clinical manifestation of vesicular lesions. The clinical presentation is influenced by the portal of entry, the immune status of the host, and whether the infection is primary or recurrent. Affecting 60% to 95% of adults, herpesvirus-associated infections include gingivostomatitis, orofacial and genital herpes,and primary varicella and herpes zoster. Symptomatology, treatment, and potential complications vary based on primary and recurrent infections as well as the patient's immune status.

Rapid detection and diagnosis of herpetic keratitis using quantitative microfluidic polymerase chain reaction system for herpes simplex and varicella-zoster virus DNA: a case series

BACKGROUND

A microfluidic real-time polymerase chain reaction (PCR) system can rapidly detect the viral DNA in specimens. Detection of herpes simplex virus (HSV) and varicella-zoster virus (VZV) DNA in tears is a useful diagnostic tool for herpes simplex virus keratitis (HSK) and herpes zoster ophthalmicus (HZO).

METHODS

In total, 20 patients were included in this cross-sectional study. Among them, 8 patients with infectious epithelial HSK and 12 patients with HZO were included in HSK and HZO groups, respectively. In addition, 8 patients with non-herpetic keratitis and 4 healthy individuals without keratitis were included in the control group. Numbers of HSV and VZV DNA copies in tears of all patients and individuals were evaluated using a microfluidic real-time PCR system. Regarding HSV/VZV DNA test, tear specimens were collected by filter paper method using Schirmer's test paper, and subsequently, DNA was extracted from the filter paper using an automated nucleic acid extractor. Afterward, quantitative PCR was performed using a microfluidic real-time PCR system.

RESULTS

From tear collection to real-time PCR result determination, the HSV/VZV DNA test took approximately 40 min. In the HSK group, the sensitivity and specificity of the HSV DNA tests were 100% each. The median value (range) of number of HSV DNA copies for affected eyes was 3.4 × 10⁵ copies/μL (under a lower detection limit of 7.6). In the HZO group, the sensitivity and specificity of the VZV DNA tests were 100% each. The median value (range) of number of VZV DNA copies for affected eyes was 5.3 × 10⁵ copies/μL (under a lower detection limit of 5.6 × 10^-2).

CONCLUSION

In conclusion, quantitative PCR for HSV and VZV DNA in tears using a microfluidic real-time PCR system is useful for diagnosing and monitoring HSK and HZO.

Diagnostic and Immunologic Testing for Varicella in the Era of High-Impact Varicella Vaccination: An Evolving Problem

The clinical presentation of varicella in unvaccinated persons, with skin vesicles and scabs, has facilitated the use of rapid diagnostic methods for confirming disease. Polymerase chain reaction (PCR) assays are the diagnostic method of choice. The sharp decline in unmodified cases of varicella due to the US varicella vaccination program has led to fewer healthcare providers being familiar with varicella presentation and an increased reliance on laboratory diagnosis to confirm suspected cases. The mild, atypical presentation of the disease in vaccinated persons (fewer skin lesions, mostly maculopapular) has made it more challenging for providers to recognize and also to collect samples to detect the virus. Nonetheless, PCR is highly sensitive and specific in confirming modified disease if adequate samples are provided. While a positive PCR result is confirmatory, interpreting a negative result can prove to be more challenging in determining whether suspected varicella is falsely negative or attributable to other causes. Enhanced education of healthcare providers is critical for adequate specimen collection from modified varicella cases. In addition, more sensitive commercial serologic assays are needed in the United States for varicella immunity testing in the vaccine era.

Viral, bacterial, and fungal infections of the oral mucosa: Types, incidence, predisposing factors, diagnostic algorithms, and management

For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.

The positive duration of varicella zoster immunoglobulin M antibody test in herpes zoster

Laboratory tests for herpes zoster (HZ) are required to confirm varicella zoster virus (VZV) infection, especially when a skin lesion is not typical or apparent. The serological test for VZV IgM antibody is simple and cost-effective; however, the change in the VZV IgM-positive rate over the time course of the disease has not been investigated. Therefore, we conducted an observational study to evaluate the positive rate of VZV IgM results during the time course of HZ and estimate the VZV IgM-positive period.After obtaining serum from patients with typical HZ, the VZV IgM titer was examined using enzyme-linked immunosorbent assay methods. After logarithmic transformation of the VZV IgM titer and the period after the onset of HZ, regression analysis was performed with the 2 transformed variables.A total of 62 patients were included in this study, and VZV IgM antibody was positive only in 23 patients (37%). The estimated antibody-positive period after HZ onset was 3.5 weeks (95% confidence interval 2.8-4.6 weeks).These findings suggest that the serological diagnosis of VZV IgM to confirm HZ is only useful within 3.5 weeks after the onset of symptoms.

Eczema Herpeticum Localized to Area of Tinea Cruris

Eczema herpeticum (EH) has been reported in association with various skin abnormalities. We experienced a patient with tinea cruris who developed EH within a fungal infection. To our knowledge, dermatophyte infection as an underlying cutaneous disorder for EH has not been previously described in the English literature.

Update on oral herpes virus infections

Oral herpes virus infections (OHVIs) are among the most common mucosal disorders encountered by oral health care providers. These infections can affect individuals at any age, from infants to the elderly, and may cause significant pain and dysfunction. Immunosuppressed patients may be at increased risk for serious and potential life-threatening complications caused by OHVIs. Clinicians may have difficulty in diagnosing these infections because they can mimic other conditions of the oral mucosa. This article provides oral health care providers with clinically relevant information regarding etiopathogenesis, diagnosis, and management of OHVIs.

Diagnostic methods and management strategies of herpes simplex and herpes zoster infections

Herpes infections are extremely prevalent in the adult population. Recognizing early signs and symptoms is essential to provide effective treatment. The immunocompromised population presents treatment challenges requiring prolonged antiviral therapy and more frequent recurrences. Viral culture is often considered the gold standard diagnostic technique; however, polymerase chain reaction (PCR) should be done in tandem with culture especially for varicella zoster virus infections. Antivirals can decrease viral shedding, recurrences of herpes simplex, and hasten healing of herpes zoster. Herpes virus can be a challenging entity to treat with significant morbidity (both physically and psychologically).

Spinal Arteriovenous Malformation Masquerating Zoster Sine Herpete

Zoster sine herpete (ZSH) is difficult to diagnosis during an acute period due to the absence of the characteristic zosteriform dermatomal rash; therefore, progression to postherpetic neuralgia is more common than typical zoster. In addition, misdiagnosis of other neuropathic pain as ZSH is common in clinical situations. Here, we report a case of spinal arteriovenous malformation that mimics ZSH. This is a rare condition; therefore, high clinical suspicion for a correct diagnosis and proper examination are not easy. However, early diagnosis and definitive treatment are essential to prevent neurologic deficit and mortality.

The clinical spectrum and therapeutic challenge of eczema herpeticum

We present 5 cases of eczema herpeticum in patients with severe recalcitrant atopic dermatitis to illustrate the range of possible clinical findings and supporting laboratory data that can obscure the diagnosis and complicate treatment. Major issues include: the need for aggressive laboratory evaluation (molecular diagnostics, viral cultures, skin biopsy, serology); the possibility of recurrent or chronic infection; the value of empiric antiviral therapy; the possibility of infection with thymidine-kinase resistant strains; and the importance of achieving control over the dermatitis with nonmyelosuppressive immunomodulating agents such as intravenous immunoglobulin or interferon gamma for dermatitis that requires systemic treatment.

Early detection of Varicella-Zoster virus (VZV)-specific T-cells before seroconversion in primary varicella infection: case report

Here we report the case of a 54-year old, immunocompetent German patient with primary varicella whose Varicella-Zoster Virus (VZV)-specific T-cell responses could be detected early in infection and before the onset of seroconversion. This case demonstrates that the detection of VZV-specific T-cells may under certain circumstances support the diagnosis of a primary varicella infection, as for example in cases of atypical or subclinical varicella or in the absence of detectable VZV DNA in plasma.

Impact of varicella vaccine on varicella-zoster virus dynamics

The licensure and recommendation of varicella vaccine in the mid-1990s in the United States have led to dramatic declines in varicella incidence and varicella-related deaths and hospitalizations. Varicella outbreaks remain common and occur increasingly in highly vaccinated populations. Breakthrough varicella in vaccinated individuals is characteristically mild, typically with fewer lesions that frequently do not progress to a vesicular stage. As such, the laboratory diagnosis of varicella has grown increasingly important, particularly in outbreak settings. In this review the impact of varicella vaccine on varicella-zoster virus (VZV) disease, arising complications in the effective diagnosis and monitoring of VZV transmission, and the relative strengths and limitations of currently available laboratory diagnostic techniques are all addressed. Since disease symptoms often resolve in outbreak settings before suitable test specimens can be obtained, the need to develop new diagnostic approaches that rely on alternative patient samples is also discussed.

Reintroducing the Tzanck smear

The Tzanck smear is a rapid and simple technique that can be performed in the clinic or doctor's office with minimal patient discomfort or cost. It is known to most dermatologists as a rapid test for diagnosing herpes virus infections. Its use, however, can be more widely applied, including in the diagnosis of pustular diseases of the newborn, cutaneous infections, vesiculobullous diseases, and non-melanoma skin cancers. Material is gently scraped from the base of a vesicle, blister, or pustule or directly from the lesion or tumor. Typically, the material is allowed to air dry after which it can then be stained with a variety of stains, including Giemsa, toluidine blue, and methylene blue. The Tzanck smear should not be used to replace more standard diagnostic techniques, but rather as an adjunct to the physical examination.

Application of immunohistochemistry to infections

CONTEXT

Pathologists play an important role in the diagnosis or exclusion of infectious diseases. Traditionally, the diagnosis of infectious diseases rely on serologic assays and cultures. Serologic results may be difficult to interpret in the setting of immunosuppression, fresh tissue is not always available for culture, and culture of fastidious pathogens can be difficult and may take weeks or months to yield a result. Although some microorganisms or their cytopathic effects may be readily identifiable on routine and/or histochemical stains, often these changes are not specific or are sparse in the sample evaluated. In these cases, additional immunohistochemical stains are often needed to establish the diagnosis of infection.

OBJECTIVE

To review the current value and limitations of the use of immunohistochemistry in the diagnosis of infectious diseases in formalin-fixed tissue samples.

DATA SOURCES

Literature in Medline and the authors' own experience.

CONCLUSIONS

Immunohistochemistry has proven to be a useful tool in the diagnosis of infectious diseases in tissue samples. Immunohistochemistry is especially useful in the identification of microorganisms that are present in low numbers, stain poorly, are fastidious to grow, are noncultivable, or exhibit an atypical morphology. Finally, it is important to remember that there may be widespread occurrence of common antigens among bacteria and pathogenic fungi and both monoclonal and polyclonal antibodies must be tested for possible cross-reactivity with other organisms.

Comparison of the Tzanck test and polymerase chain reaction in the diagnosis of cutaneous herpes simplex and varicella zoster virus infections

BACKGROUND

Although the diagnosis of herpes simplex virus (HSV) and varicella zoster virus (VZV) infections is usually made clinically, the Tzanck test, electron microscopy, viral culture, polymerase chain reaction (PCR), and serologic tests can be utilized to verify the diagnosis.

METHODS

We conducted a study on a total of 98 patients (77 patients with recurrent herpes simplex and 21 patients with herpes zoster) to evaluate the reliability and reproducibility of the Tzanck test in comparison with PCR.

RESULTS

In herpes virus infections, the general positivity rates of the Tzanck test and PCR were 61.2% and 79.6%, respectively. The difference between the positivity rates of the two tests was statistically significant. The positivity rates of the tests differed according to the type and duration of the lesions.

CONCLUSIONS

Although PCR was superior to the Tzanck test, the Tzanck test has also been proven to be a reliable diagnostic method, with a sensitivity of 76.9% and a specificity of 100%. We recommend the use of this easy, quick, reproducible, and inexpensive diagnostic test more often in dermatologic practice, especially in cutaneous herpes virus infections.

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

Herpes simplex virus-1 (HSV-1) infection in radiation-induced oral mucositis

GOAL OF WORK

The aim of the study was to investigate the incidence of herpes simplex virus-1 (HSV-1) infection in mucositis during head and neck cancer radiotherapy.

PATIENTS AND METHODS

Sixty patients with malignant head and neck tumor, eligible to receive radiotherapy, who were referred to the Dental Oncology Unit, entered the study. Sixteen patients (26.6%) received concomitant chemotherapy. Mucositis was recorded weekly. Smears taken from the ulcers of mucositis grade 2, or 3, or 4 were stained with Papanicolaou and alkaline phosphatase/antialkaline phosphatase immunocytochemical method to identify HSV-1.

MAIN RESULTS

Forty-eight of all 60 patients developed ulcerative mucositis. Smear was available from 29 of 48 patients with ulcerations. HSV-1 infection was identified in 14 of 29 smears available (48.2%). Mucositis healed or was reduced after 1 week of antiviral treatment in 11 of those 14 HSV-1-positive patients; 3 patients responded to 1 g/day of valacyclovir, 7-2 g/day, and 1 patient responded to i.v. acyclovir. Ulcerations recurred after quitting antivirals. Three patients did not respond to 1 g/day of valacyclovir. No HSV-1-negative patient responded to acyclovir (P = 0.000).

CONCLUSION

HSV-1 was isolated from 14 of 29 available smears taken from 48 patients with ulcerative mucositis. The incidence of HSV-1 infection during radiotherapy was estimated as being 14 of all 48 patients at risk (29.1%). Healing or reduction in the grade of mucositis after antivirals in HSV-1 positive patients, combined with the negative response to antivirals in HSV-1 negative patients, denoted that HSV-1 infection was a component of ulcerative radiation mucositis in those HSV-1-positive patients.

Oral herpetic infections (HSV 1-8)

Oral herpes virus infections are commonly seen by the dental practitioner. Saliva is a reservoir for the herpes virus, and a variety of infections, both localized and systemic, may be induced by the virus. Patients who are immunocompromised may be at risk for serious and potentially life-threatening complications of herpes virus infections. This article highlights the basic virology and clinical manifestations of herpetic infections and the differential diagnosis and management of oral herpes virus infections.

Update on herpesvirus infections

Herpesviruses are responsible for many illnesses that affect the oral and maxillofacial region. The most common of these are primary or recurrent HSV infection, but knowledge of the manifestations of the eight herpesviruses that cause infections in humans will provide clinicians with a better understanding and basis for diagnosing and managing patients with these diseases. Immunocompromised patients are at greater risk for serious illness: therefore, clinicians treating transplant patients, patients receiving cancer chemotherapy, or HIV-infected individuals should be aware of the various clinical manifestations of infection with herpesviruses.

Herpes zoster of the penis: an unusual location for a common eruption

Herpes zoster is an acute vesiculobullous eruption estimated to affect 10% to 20% of the population. The diagnosis usually can be based on clinical features alone, but laboratory studies may be needed for definitive diagnosis, particularly in atypical presentations.

Herpes simplex viruses 1 and 2

An increased understanding of the pathogenesis and transmission of HSV infections and the development of sensitive type-specific diagnostic tests have helped develop effective prophylactic and therapeutic antiviral drug regimens. Effective medications have been available for quite some time, but the most optimal regimens are still under investigation. Advances in the treatment of atypical presentations of HSV infection (such as the use of cidofovir gel for the treatment of acyclovir-resistant HSV) are promising. Newer treatments, such as resiquimod, actually may alter the course of HSV infection, reducing the severity and frequency of recurrences. Vaccines are being explored as preventive and therapeutic measures against HSV.

The importance of specific virus diagnosis and monitoring for antiviral treatment

Antiviral treatment, rapid viral diagnosis and point-of-care diagnostics are all relatively new, and their appropriate use not fully appreciated or evaluated. In this article, the need for laboratory diagnosis in relation to antiviral treatment, and practical approaches are discussed, with influenza and herpes simplex virus (HSV) as examples.

Infectious disease pathology

The anatomic pathologist performs an important role in the diagnosis or exclusion of infectious diseases. The morphologic interpretation of biopsies and cytologic preparations allows for the definitive establishment or exclusion of a wide variety of diseases. Once the pathologist has determined that a disease is likely to be due to an infection and has characterized the inflammatory response, associated microorganisms or viral-associated cytopathic effects should be recorded. Although some microorganisms or their cytopathic effects may be clearly visible on routine hematoxylin and eosin-stained sections, additional histochemical stains are often needed for their complete characterization. Highly specific molecular techniques, such as immunohistochemistry, in situ hybridization, and nucleic acid amplification, may be needed in certain instances to establish the diagnosis of infection. Through appropriate morphologic diagnoses and interlaboratory communication and collaboration, the anatomic pathologist contributes greatly to the diagnosis and treatment of infectious diseases.

Longitudinal analysis of varicella-zoster virus DNA on the ocular surface associated with herpes zoster ophthalmicus

PURPOSE

Longitudinal analysis of varicella-zoster virus DNA on the ocular surface of patients with herpes zoster ophthalmicus.

METHODS

Clinical specimens were obtained from the bulbar conjunctival surface with a cotton-tipped swab at weekly intervals for 6 consecutive weeks from 21 patients with acute ophthalmic zoster with a skin rash duration of less than 7 days. All patients received oral valacyclovir 1000 mg three times daily for 10 days without additional corticosteroids. The swabs were analyzed by means of polymerase chain reaction for the presence of varicella-zoster virus and herpes simplex virus type 1 DNA. Conjunctival swabs were also obtained from a control group of 20 patients with cataract.

RESULTS

On inclusion, varicella-zoster virus DNA was present on the ocular surface of 19 of the 21 patients. Six varicella-zoster virus DNA-positive patients had no signs of ocular inflammation. All control swabs were negative for both varicella-zoster virus and herpes simplex virus DNA. The duration of varicella-zoster virus DNA detection from rash onset varied from 2 to 34 days. The number of days between the onset of herpes zoster skin rash and the latest positive varicella-zoster virus DNA test was significantly longer in patients whose age was equal to or above the median age of 66 years than in the younger patients (Mann-Whitney test: P =.0004). At 6-week follow-up, all conjunctival swabs were negative for varicella-zoster virus DNA. However, at that time, the eyes of seven patients were still inflamed.

CONCLUSION

The duration of varicella-zoster virus DNA shedding in herpes zoster ophthalmicus is highly variable and age dependent, and is probably related to the host immune response.

Detection of varicella-zoster virus and herpes simplex virus by the polymerase chain reaction with degenerate primers

Varicella-zoster virus (VZV) and herpes simplex virus (HSV) are human pathogens of significance involved in multiple diseases with either typical or atypical clinical features. In neonates and immunocompromised patients these alphaherpesviruses may cause life-threatening diseases such as encephalitis. Detection of VZV by virus culture is difficult. Polymerase chain reaction (PCR) is quicker and more sensitive and applicable in most clinical microbiological laboratories. Using degenerate primers, glycoprotein B (gB) DNA was amplified from all alphaherpesvirus field strains present in clinical samples. The amplification of gB allowed virus typing of VZV, HSV-1 and HSV-2 using restriction enzyme digestion of the PCR products. Degenerate primers can replace conventional primers in diagnostic PCR without loss of sensitivity and specificity.

Laboratory diagnosis of herpes zoster

Virological diagnosis of zoster should be rapid when effective antiviral chemotherapy is being considered. In the present study, vesicle specimens of 100 patients with zoster were analysed by detecting viral DNA using polymerase chain reaction (PCR). The findings were compared with those obtained by traditional virological and serological methods. PCR results confirmed the clinical diagnosis of zoster in 95%. Primers selected from varicella-zoster virus (VZV) gene 28 proved to be most sensitive. The sensitivity of virus culture was 20% (specificity 100%), of direct immunofluorescent VZV-specific antigen staining in vesicle samples 82% (specificity 76%), and in 48% there was a serological response to specific IgM and IgA antibodies within 4 days after the onset of rash. These findings suggest that PCR is the method of choice for rapid laboratory diagnosis of zoster.

Comparative study of transfer factor and acyclovir in the treatment of herpes zoster

Reactivation of varicella herpes virus (VHV), latent in individuals who have previously suffered varicella, gives rise to herpes zoster and in some cases leads to a sequela of post herpetic neuritis with severe pain which is refractory to analgesics. Many different antiviral agents have been tried without achieving satisfactory results. Of all the antiviral agents employed, acyclovir has been the most successful in reducing post herpetic pain. However acyclovir has not been as reliable as interferon alpha (IFN-alpha). We have previously looked into the use of transfer factor (TF) as a modulator of the immune system, specifically with respect to its effectiveness in the treatment of herpes zoster. In this work findings from a comparative clinical evaluation are presented. A double blind clinical trial of TF vs acyclovir was carried out in which 28 patients, presenting acute stage herpes zoster, were randomly assigned to either treatment group. Treatment was administered for seven days and the patients were subsequently submitted to daily clinical observation for an additional 14 days. An analogue visual scale was implemented in order to record pain and thereby served as the clinical parameter for scoring results. The group treated with TF was found to have a more favorable clinical course, P < or = 0.015. Laboratory tests to assess the immune profile of the patients were performed two days prior and 14 days after initial treatment. The results of these tests showed an increase in IFN-gamma levels, augmentation in the CD4+ cell population but not the percentage of T rosettes in the TF treated group. These parameters were however insignificantly modified in patients receiving acyclovir. Although TF treated patients showed an increase in CD4+ counts these cells remained below the levels for healthy individuals. The fact that IFN-gamma levels as well as the counts for CD4+ cells rose in the TF treated group and not in the acyclovir one is very significant and confirms the immunomodulating properties of TF.

The clinical characteristics of intraoral herpes simplex virus infection in 52 immunocompetent patients

OBJECTIVE

Intraoral herpes simplex virus infection is commonly mistaken for recurrent aphthous stomatitis. The purpose of this study was to describe the clinical features of intraoral herpes simplex virus infection.

STUDY DESIGN

Fifty-two immunocompetent patients with culture-positive intraoral herpes simplex virus infection were studied.

RESULTS

The median age of the patients was 42 years. One third of the patients exhibited single ulcers; the remaining patients displayed multiple lesions. In 47 of 52 cases, the ulcers occurred on keratinized surfaces of the oral cavity; however, 5 patients had persistent ulcerations on nonkeratinized mucosa, a typical feature of herpetic ulcers in immunosuppressed patients. Of 27 patients with histories of recurrences, 22 were previously incorrectly diagnosed with recurrent aphthous stomatitis.

CONCLUSIONS

Herpes simplex virus infection of the oral cavity can usually be differentiated from other causes of recurrent oral ulcerations on the basis of its clinical appearance and distribution. The recognition of atypical features may prevent unnecessary and costly treatments for unrelated though clinically similar-appearing disorders.

Segmental neurofibromatosis: case reports and review

Segmental neurofibromatosis (neurofibromatosis type V) is a rare disorder characterized by café-lu-lait macules and neurofibromas, or only neurofibromas, limited to one region of the body. Three patients with segmental neurofibromatosis are described, and cases of this condition in the world literature are reviewed. Segmental neurofibromatosis has only been described in 82 patients, including our three. The median age at onset was 28 years and the incidence was higher in women (58%). The neurofibromas most commonly occupied either a cervical or thoracic dermatome and were unilateral, occurring more often on the right side (43 patients) than the left (34 patients). Café-au-lait macules were present in 26% of patients. Axillary freckling was described in only nine patients. Disease-associated systemic involvement was uncommon. Most patients with segmental neurofibromatosis (93%) do not have a family history of neurofibromatosis.

What is new in clinical research of viral diseases of the skin

Viral diseases of the skin have become a much more serious problem with the increasing number of patients immunosuppressed by either AIDS or cancer chemotherapy. The emphasis in research on the diagnosis and treatment of these diseases is similar to that on the bacterial diseases several decades ago.

Rapid detection and distinction of cutaneous herpesvirus infections by direct immunofluorescence

BACKGROUND

Optimal management of cutaneous herpes simplex virus (HSV) and varicellazoster virus (VZV) infections requires rapid, accurate distinction between these pathogens.

OBJECTIVE

In a mixed-case series of suspected cutaneous herpesvirus infections, we compared the diagnostic utility of viral culture and direct immunofluorescence (DIF) using a panel of fluoresceinated monoclonal antibodies against HSV and VZV.

METHODS

Epifluorescence microscopy of smears and viral culture were performed in parallel on 58 lesions.

RESULTS

DIF and culture were equally sensitive (88%) in HSV infections, whereas DIF was four times as sensitive as culture (100% vs 18%) in VZV. DIF either refuted an incorrect clinical diagnosis or permitted definitive laboratory diagnosis of a clinically indeterminate lesion in 7 (12%) of 58 lesions tested.

CONCLUSION

DIF is a rapid, simple, sensitive, specific, cost-effective, and clinically useful technique for detecting and distinguishing cutaneous HSV and VZV infections.